Explainers - BBC News

<!DOCTYPE html> <html lang="en" id="responsive-news"> <head prefix="og: http://ogp.me/ns#"><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("http://www.bbc.com/news/explainers","20180130113126","https://web.archive.org/","web","/_static/", "1517311886"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <title>Explainers - BBC News</title> <link rel="preload" as="style" href="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/stylesheets/services/news/compact.css" media="(max-width: 599px)"> <link rel="preload" as="style" href="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/stylesheets/services/news/tablet.css" media="(min-width: 600px)"> <link rel="preload" as="style" href="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/stylesheets/services/news/wide.css" media="(min-width: 1008px)"> <link rel="dns-prefetch" href="https://web.archive.org/web/20180130113126/https://ssl.bbc.co.uk/"> <link rel="dns-prefetch" href="https://web.archive.org/web/20180130113126/http://sa.bbc.co.uk/"> <link rel="dns-prefetch" href="https://web.archive.org/web/20180130113126/http://ichef-1.bbci.co.uk/"> <link rel="dns-prefetch" href="https://web.archive.org/web/20180130113126/http://ichef.bbci.co.uk/"> <link rel="dns-prefetch" href="//web.archive.org/web/20180130113126/http://c.go-mpulse.net/"> <meta name="x-country" content="us"> <meta name="x-audience" content="US"> <meta name="CPS_AUDIENCE" content="US"> <meta name="CPS_CHANGEQUEUEID" content="115195995"> <link rel="canonical" href="https://web.archive.org/web/20180130113126/http://www.bbc.com/news/explainers"> <link rel="alternate" hreflang="en-gb" href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/explainers"> <link rel="alternate" hreflang="en" href="https://web.archive.org/web/20180130113126/http://www.bbc.com/news/explainers"> <meta property="og:title" content="Explainers - BBC News"/> <meta property="og:type" content="website"/> <meta property="og:description" content=""/> <meta property="og:site_name" content="BBC News"/> <meta property="og:locale" content="en_GB"/> <meta property="article:author" content="https://www.facebook.com/bbcnews"/> <meta property="article:section" content="Explainers"/> <meta property="og:url" content="https://web.archive.org/web/20180130113126/http://www.bbc.com/news/explainers"/> <meta property="og:image" content="https://web.archive.org/web/20180130113126im_/http://www.bbc.co.uk/news/special/2015/newsspec_10857/bbc_news_logo.png?cb=1"/> <meta property="og:image:alt" content="BBC News. BBC News"/> <meta property="fb:pages" content="1143803202301544,317278538359186,1392506827668140,742734325867560,185246968166196,156060587793370,137920769558355,193435954068976,21263239760,156400551056385,929399697073756,154344434967,228735667216,80758950658,260212261199,294662213128,1086451581439054,283348121682053,295830058648,239931389545417,304314573046,310719525611571,647687225371774,1159932557403143,286567251709437,1731770190373618,125309456546,163571453661989,285361880228,512423982152360,238003846549831,176663550714,260967092113,118450564909230,100978706649892,15286229625,122103087870579,120655094632228,102814153147070,124715648647,153132638110668,150467675018739"/> <meta name="twitter:card" content="summary_large_image"> <meta name="twitter:site" content="@BBCWorld"> <meta name="twitter:title" content="Explainers - BBC News"> <meta name="twitter:description" content=""> <meta name="twitter:creator" content="@BBCWorld"> <meta name="twitter:image:src" content="http://www.bbc.co.uk/news/special/2015/newsspec_10857/bbc_news_logo.png?cb=1"> <meta name="twitter:image:alt" content="BBC News"/> <meta name="twitter:domain" content="www.bbc.com"> <script type="application/ld+json"> {"@context":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/schema.org","@type":"WebPage","url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/explainers","publisher":{"@type":"NewsMediaOrganization","name":"BBC News","logo":{"@type":"ImageObject","url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.co.uk\/news\/special\/2015\/newsspec_10857\/bbc_news_logo.png?cb=1"}},"description":null,"name":"Explainers - BBC News"} </script> <script type="application/ld+json"> {"@context":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/schema.org","@type":"ItemList","url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/explainers","itemListElement":[{"@type":"ListItem","position":1,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/business-42705641"},{"@type":"ListItem","position":2,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/uk-politics-42860044"},{"@type":"ListItem","position":3,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/world-europe-42738511"},{"@type":"ListItem","position":4,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/uk-42818467"},{"@type":"ListItem","position":5,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/world-europe-42747002"},{"@type":"ListItem","position":6,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/uk-42748203"},{"@type":"ListItem","position":7,"url":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/news\/uk-scotland-scotland-politics-42803031"}]} </script> <meta name="apple-mobile-web-app-title" content="BBC News"> <link rel="apple-touch-icon-precomposed" sizes="57x57" href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/apple-touch-icon-57x57-precomposed.png"> <link rel="apple-touch-icon-precomposed" sizes="72x72" href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/apple-touch-icon-72x72-precomposed.png"> <link rel="apple-touch-icon-precomposed" sizes="114x114" href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/apple-touch-icon-114x114-precomposed.png"> <link rel="apple-touch-icon-precomposed" sizes="144x144" href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/apple-touch-icon.png"> <link rel="apple-touch-icon" href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/apple-touch-icon.png"> <link rel="apple-touch-startup-image" href="http://static.bbci.co.uk/news/1.226.02302/web-app-launch-icon.png"> <meta name="application-name" content="BBC News"> <meta name="msapplication-TileImage" content="BBC News"> <meta name="msapplication-TileColor" content="#bb1919"> <meta name="mobile-web-app-capable" content="yes"> <meta http-equiv="cleartype" content="on"> <meta name="robots" content="NOODP,NOYDIR"/> <meta name="theme-color" content="#bb1919"> <script type="text/javascript">var _sf_startpt=(new Date()).getTime()</script> <script> (function() { if (navigator.userAgent.match(/IEMobile\/10\.0/)) { var msViewportStyle = document.createElement("style"); msViewportStyle.appendChild( document.createTextNode("@-ms-viewport{width:auto!important}") ); document.getElementsByTagName("head")[0].appendChild(msViewportStyle); } })(); </script> <script>window.fig = window.fig || {}; window.fig.async = true;</script> <meta property="fb:app_id" content="1609039196070050"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta property="fb:admins" content="100004154058350"/> <script type="text/javascript">window.bbcredirection={geo:true}</script>  <link rel="stylesheet" href="https://web.archive.org/web/20180130113126cs_/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/style/orb.min.css">    <script class="js-require-lib" src="https://web.archive.org/web/20180130113126js_/http://static.bbci.co.uk/frameworks/requirejs/lib.js"></script> <script type="text/javascript"> bbcRequireMap = {"jquery-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jquery/0.4.1/sharedmodules/jquery-1.7.2", "jquery-1.4":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jquery/0.4.1/sharedmodules/jquery-1.4", "jquery-1.9":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jquery/0.4.1/sharedmodules/jquery-1.9.1", "jquery-1.12":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jquery/0.4.1/sharedmodules/jquery-1.12.0.min", "jquery-2.2":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jquery/0.4.1/sharedmodules/jquery-2.2.0.min", "istats-1":"//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/nav-analytics/0.1.0-43/js/istats-1", "swfobject-2":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/swfobject/0.1.10/sharedmodules/swfobject-2", "demi-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/demi/0.10.1/sharedmodules/demi-1", "gelui-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/gelui/0.9.13/sharedmodules/gelui-1", "cssp!gelui-1/overlay":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/gelui/0.9.13/sharedmodules/gelui-1/overlay.css", "relay-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/relay/0.2.6/sharedmodules/relay-1", "clock-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/clock/0.1.9/sharedmodules/clock-1", "canvas-clock-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/clock/0.1.9/sharedmodules/canvas-clock-1", "cssp!clock-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/clock/0.1.9/sharedmodules/clock-1.css", "jssignals-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jssignals/0.3.6/modules/jssignals-1", "jcarousel-1":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/jcarousel/0.1.10/modules/jcarousel-1", "bump-3":"//web.archive.org/web/20180130113126/http://emp.bbci.co.uk/emp/bump-3/bump-3"}; require({ baseUrl: 'https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/', paths: bbcRequireMap, waitSeconds: 30 }); </script> <script type="text/javascript">/*<![CDATA[*/ if (typeof bbccookies_flag === 'undefined') { bbccookies_flag = 'ON'; } showCTA_flag = true; cta_enabled = (showCTA_flag && (bbccookies_flag === 'ON')); (function(){var m="ckns_policy",q="Thu, 01 Jan 1970 00:00:00 GMT",i={ads:true,personalisation:true,performance:true,necessary:true};function c(u){if(c.cache[u]){return c.cache[u]}var t=u.split("/"),v=[""];do{v.unshift((t.join("/")||"/"));t.pop()}while(v[0]!=="/");c.cache[u]=v;return v}c.cache={};function a(u){if(a.cache[u]){return a.cache[u]}var v=u.split("."),t=[];while(v.length&&"|co.uk|com|".indexOf("|"+v.join(".")+"|")===-1){if(v.length){t.push(v.join("."))}v.shift()}c.cache[u]=t;return t}a.cache={};function s(t,y,u){var E=[""].concat(a(window.location.hostname)),B=c(window.location.pathname),D="",w,C;for(var x=0,A=E.length;x<A;x++){w=E[x];for(var v=0,z=B.length;v<z;v++){C=B[v];D=t+"="+y+";"+(w?"domain="+w+";":"")+(C?"path="+C+";":"")+(u?"expires="+u+";":"");bbccookies.set(D,true)}}}window.bbccookies={POLICY_REFRESH_DATE_MILLIS:new Date(2015,4,21,0,0,0,0).getTime(),POLICY_EXPIRY_COOKIENAME:"ckns_policy_exp",_setEverywhere:s,cookiesEnabled:function(){var t="ckns_testcookie"+Math.floor(Math.random()*100000);this.set(t+"=1");if(this.get().indexOf(t)>-1){e(t);return true}return false},get:function(){return document.cookie},getCrumb:function(t){if(!t){return null}return decodeURIComponent(document.cookie.replace(new RegExp("(?:(?:^|.*;)\\s*"+encodeURIComponent(t).replace(/[\-\.\+\*]/g,"\\$&")+"\\s*\\=\\s*([^;]*).*$)|^.*$"),"$1"))||null},policyRequiresRefresh:function(){var u=new Date();u.setHours(0);u.setMinutes(0);u.setSeconds(0);u.setMilliseconds(0);if(bbccookies.POLICY_REFRESH_DATE_MILLIS<=u.getTime()){var t=bbccookies.getCrumb(bbccookies.POLICY_EXPIRY_COOKIENAME);if(t){t=new Date(parseInt(t));t.setYear(t.getFullYear()-1);return bbccookies.POLICY_REFRESH_DATE_MILLIS>=t.getTime()}else{return true}}else{return false}},_setPolicy:function(t){return f.apply(this,arguments)},readPolicy:function(){return l.apply(this,arguments)},_deletePolicy:function(){s(m,"",q)},_isConfirmed:function(){return n()!==null},_acceptsAll:function(){var t=l();return t&&!(j(t).indexOf("0")>-1)},_getCookieName:function(){return b.apply(this,arguments)},_showPrompt:function(){var t=((!this._isConfirmed()||this.policyRequiresRefresh())&&window.cta_enabled&&this.cookiesEnabled()&&!window.bbccookies_disable);return(window.orb&&window.orb.fig)?t&&(window.orb.fig("no")||window.orb.fig("ck")):t},_getPolicy:this.readPolicy};function b(u){var t=(""+u).match(/^([^=]+)(?==)/);return(t&&t.length?t[0]:"")}function j(t){return""+(t.ads?1:0)+(t.personalisation?1:0)+(t.performance?1:0)}function f(x){if(typeof x==="undefined"){x=i}if(typeof arguments[0]==="string"){var u=arguments[0],w=arguments[1];if(u==="necessary"){w=true}x=l();x[u]=w}else{if(typeof arguments[0]==="object"){x.necessary=true}}var v=new Date();v.setYear(v.getFullYear()+1);bbccookies.set(m+"="+j(x)+";domain=bbc.co.uk;path=/;expires="+v.toUTCString()+";");bbccookies.set(m+"="+j(x)+";domain=bbc.com;path=/;expires="+v.toUTCString()+";");bbccookies.set(m+"="+j(x)+";domain=bbci.co.uk;path=/;expires="+v.toUTCString()+";");var t=new Date(v.getTime());t.setMonth(t.getMonth()+1);bbccookies.set(bbccookies.POLICY_EXPIRY_COOKIENAME+"="+v.getTime()+";domain=bbc.co.uk;path=/;expires="+t.toUTCString()+";");bbccookies.set(bbccookies.POLICY_EXPIRY_COOKIENAME+"="+v.getTime()+";domain=bbc.com;path=/;expires="+t.toUTCString()+";");bbccookies.set(bbccookies.POLICY_EXPIRY_COOKIENAME+"="+v.getTime()+";domain=bbci.co.uk;path=/;expires="+t.toUTCString()+";");return x}function o(t){if(t===null){return null}var u=t.split("");return{ads:!!+u[0],personalisation:!!+u[1],performance:!!+u[2],necessary:true}}function n(){var t=new RegExp("(?:^|; ?)"+m+"=(\\d\\d\\d)($|;)"),u=document.cookie.match(t);if(!u){return null}return u[1]}function l(t){var u=o(n());if(!u){u=i}if(t){return u[t]}else{return u}}function e(t){return document.cookie=t+"=;expires="+q+";"}var g=!(window.bbccookies_flag==="ON"&&!bbccookies._acceptsAll()&&!window.bbccookies_disable);var k={},d={"personalisation":"ckps_.+|X-AB-iplayer-.+|ACTVTYMKR|BBC_EXAMPLE_COOKIE|BBCIplayer|BBCiPlayerM|BBCIplayerSession|BBCMediaselector|BBCPostcoder|bbctravel|CGISESSID|ed|food-view|forceDesktop|h4|IMRID|locserv|MyLang|myloc|NTABS|ttduserPrefs|V5|WEATHER|BBCScienceDiscoveryPlaylist_.+|bitratePref|correctAnswerCount|genreCookie|highestQuestionScore|incorrectAnswerCount|longestStreak|MSCSProfile|programmes-oap-expanded|quickestAnswer|score|servicePanel|slowestAnswer|totalTimeForAllFormatted|v|BBCwords|score|correctAnswerCount|highestQuestionScore|hploc|BGUID|BBCWEACITY|mstouch|myway|BBCNewsCustomisation|cbbc_anim|cbeebies_snd|bbcsr_usersx|cbeebies_rd|BBC-Latest_Blogs|zh-enc|pref_loc|m|bbcEmp.+|recs-.+|_lvd2|_lvs2|tick|_fcap_CAM1|_rcc2","performance":"ckpf_.+|optimizely.*|BBCLiveStatsClick|id|_em_.+|cookies_enabled|mbox|mbox-admin|mc_.+|omniture_unique|s_.+|sc_.+|adpolicyAdDisplayFrequency|s1|ns_session|ns_cookietest|ns_ux|NO-SA|tr_pr1|gvsurvey|bbcsurvey|si_v|sa_labels|obuid|mm_.+|mmid|mmcore.+|mmpa.+","ads":"ckad_.+|rsi_segs|c","necessary":"ckns_.+|BBC-UID|blq\\.dPref|SSO2-UID|BBC-H2-User|rmRpDetectReal|bbcComSurvey|IDENTITY_ENV|IDENTITY|IDENTITY-HTTPS|IDENTITY_SESSION|BBCCOMMENTSMODULESESSID|bbcBump.+|IVOTE_VOTE_HISTORY|pulse|BBCPG|BBCPGstat|ecos\\.dt"};function r(){var x=document.cookie.replace(/; +/g,";").split(";"),u,v=[];for(var w=0,t=x.length;w<t;w++){u=x[w];v.push(bbccookies._getCookieName(u))}return v}function h(w){var v=JSON.stringify(w);if(typeof(k[v])!=="undefined"){return k[v]}var u="";for(var t in w){if(w.hasOwnProperty(t)&&d[t]){if(w[t]===true){u+=(u?"|":"")+d[t]}}}k[v]=new RegExp("^("+(u?u:".*")+")$","i");return k[v]}bbccookies.getPolicyExpiryDateTime=function(){return bbccookies.POLICY_EXPIRY_COOKIENAME};bbccookies.purge=function(){var u=bbccookies.readPolicy(),w=r(),x;for(var v=0,t=w.length;v<t;v++){if(!bbccookies.isAllowed(w[v],u)){x=new Date();x.setTime(0);x=x.toUTCString();s(w[v],"deleted",x)}}};function p(){if(g){return}bbccookies.purge();contentLoaded(window,bbccookies.purge);if(window.addEventListener){window.addEventListener("beforeunload",bbccookies.purge,false)}else{if(window.attachEvent){window.attachEvent("onbeforeunload",bbccookies.purge)}else{window.onbeforeunload=bbccookies.purge}}}bbccookies.set=function(u,t){if(g){return document.cookie=u}var v=bbccookies._getCookieName(u);if(t||bbccookies.isAllowed(v)){return document.cookie=u}return null};bbccookies.isAllowed=function(v){var u=bbccookies.readPolicy();var t=h(u);return t.test(v)};p()})(); /*! * contentloaded.js * * Author: Diego Perini (diego.perini at gmail.com) * Summary: cross-browser wrapper for DOMContentLoaded * Updated: 20101020 * License: MIT * Version: 1.2 * * URL: * http://javascript.nwbox.com/ContentLoaded/ * http://javascript.nwbox.com/ContentLoaded/MIT-LICENSE * */ function contentLoaded(d,i){var c=false,h=true,k=d.document,j=k.documentElement,a=k.addEventListener,n=a?"addEventListener":"attachEvent",l=a?"removeEventListener":"detachEvent",b=a?"":"on",m=function(o){if(o.type==="readystatechange"&&k.readyState!="complete"){return}(o.type==="load"?d:k)[l](b+o.type,m,false);if(!c&&(c=true)){i.call(d,o.type||o)}},g=function(){try{j.doScroll("left")}catch(o){setTimeout(g,50);return}m("poll")};if(k.readyState==="complete"){i.call(d,"lazy")}else{if(!a&&j.doScroll){try{h=!d.frameElement}catch(f){}if(h){g()}}k[n](b+"DOMContentLoaded",m,false);k[n](b+"readystatechange",m,false);d[n](b+"load",m,false)}}if(typeof(require)==="function"&&!require.defined("orb/cookies")){define("orb/cookies",function(){return window.bbccookies})}; /*]]>*/</script> <script type="text/javascript"> define('orb/cookies', function() { return window.bbccookies; }); </script> <script type="text/javascript">/*<![CDATA[*/ (function(){window.orb={};window.orb.figState={ad:0,ap:0,ck:1,eu:1,mb:0,tb:0,uk:1,df:1};window.orb.fig=function(a){return(arguments.length)?window.orb.figState[a]:window.orb.figState};window.orb.fig.device={};window.orb.fig.geo={};window.orb.fig.user={};window.orb.fig.isDefault=function(){return window.orb.fig("df")};window.orb.fig.device.isTablet=function(){return window.orb.fig("tb")};window.orb.fig.device.isMobile=function(){return window.orb.fig("mb")};window.orb.fig.geo.isUK=function(){return window.orb.fig("uk")};window.orb.fig.geo.isEU=function(){return window.orb.fig("eu")};window.fig=window.fig||{};window.fig.manager={include:function(e){e=e||window;var g=false;var j=e.document,k=j.cookie,i=k.match(/(?:^|; ?)ckns_orb_fig=([^;]+)/),h;if(i){i=this.deserialise(decodeURIComponent(RegExp.$1));this.setFig(e,i)}if(window.fig.async&&typeof JSON!="undefined"){var b=(document.cookie.match("(^|; )ckns_orb_cachedfig=([^;]*)")||0)[2];h=b?JSON.parse(b):null;if(h){this.setFig(e,h);g=true}}var a="https://web.archive.org/web/20180130113126/https://fig.bbc.co.uk/frameworks/fig/1/fig.js";if(g){j.write('<script src="'+a+'" async><'+"/script>")}else{j.write('<script src="'+a+'"><'+"/script>")}},confirm:function(a){return true},setFig:function(a,b){(function(){a.orb=a.orb||{};a.orb.figState=b})()},deserialise:function(b){var a={};b.replace(/([a-z]{2}):([0-9]+)/g,function(){a[RegExp.$1]=+RegExp.$2});return a}}})();fig.manager.include();/*]]>*/</script>  <script type="text/javascript">window.bbcFlagpoles_istats="ON",require.config({paths:{"istats-1":"//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/nav-analytics/0.1.0-89/js/istats-1","megavolt-client":"//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/nav-analytics/0.1.0-89/js/megavolt-client"},config:{"megavolt-client":{baseUrl:"https://web.archive.org/web/20180130113126/https://mvt.api.bbc.com"}}}),require(["istats-1","orb/cookies"],function(e,t){if(t.isAllowed("s1")){e.addCollector({name:"default",url:"https://web.archive.org/web/20180130113126/https://sa.bbc.co.uk/bbc/bbc/s",separator:"&"});var a="news.explainers.page";e.setCountername(a),window.istats_countername&&e.setCountername(window.istats_countername),e.addLabels("ml_name=webmodule&ml_version=89")}});</script> <script type="text/javascript">/*<![CDATA[*/ window.bbcFlagpoles_istats = 'ON'; window.orb = window.orb || {}; if (typeof bbccookies !== 'undefined' && bbccookies.isAllowed('s1')) { var istatsTrackingUrl = '//web.archive.org/web/20180130113126/http://sa.bbc.co.uk/bbc/bbc/s?name=news.explainers.page&cps_asset_id=29240806&page_type=Index&section=%2Fnews%2Fexplainers&first_pub=2014-09-17T11%3A39%3A47%2B00%3A00&last_editorial_update=2018-01-30T08%3A28%3A09%2B00%3A00&curie=03425334-85d6-b09b-e050-380a4e801e3f%2Fdesktop%2Fdomestic&for_nation=us&app_version=1.226.0&bbc_site=news&pal_route=asset&app_type=responsive&language=en-GB&pal_webapp=tabloid&prod_name=news&app_name=news'; require(['istats-1'], function (istats) { var counterName = (window.istats_countername) ? window.istats_countername : istatsTrackingUrl.match(/[\?&]name=([^&]*)/i)[1]; istats.setCountername(counterName); istats.addLabels('cps_asset_id=29240806&page_type=Index&section=%2Fnews%2Fexplainers&first_pub=2014-09-17T11%3A39%3A47%2B00%3A00&last_editorial_update=2018-01-30T08%3A28%3A09%2B00%3A00&curie=03425334-85d6-b09b-e050-380a4e801e3f%2Fdesktop%2Fdomestic&for_nation=us&app_version=1.226.0&bbc_site=news&pal_route=asset&app_type=responsive&language=en-GB&pal_webapp=tabloid&prod_name=news&app_name=news'); var c = (document.cookie.match(/\bckns_policy=(\d\d\d)/) || []).pop() || ''; istats.addLabels({ 'blq_s': '4d', 'blq_r': '2.7', 'blq_v': 'default', 'blq_e': 'pal', 'bbc_mc': (c ? 'ad' + c.charAt(0) + 'ps' + c.charAt(1) + 'pf' + c.charAt(2) : 'not_set') } ); }); } /*]]>*/</script> <script type="text/javascript">/*<![CDATA[*/ (function(undefined){if(!window.bbc){window.bbc={}}var ROLLING_PERIOD_DAYS=30;window.bbc.Mandolin=function(id,segments,opts){var now=new Date().getTime(),storedItem,DEFAULT_START=now,DEFAULT_RATE=1,COOKIE_NAME="ckpf_mandolin";opts=opts||{};this._id=id;this._segmentSet=segments;this._store=new window.window.bbc.Mandolin.Storage(COOKIE_NAME);this._opts=opts;this._rate=(opts.rate!==undefined)?+opts.rate:DEFAULT_RATE;this._startTs=(opts.start!==undefined)?new Date(opts.start).getTime():new Date(DEFAULT_START).getTime();this._endTs=(opts.end!==undefined)?new Date(opts.end).getTime():daysFromNow(ROLLING_PERIOD_DAYS);this._signupEndTs=(opts.signupEnd!==undefined)?new Date(opts.signupEnd).getTime():this._endTs;this._segment=null;if(typeof id!=="string"){throw new Error("Invalid Argument: id must be defined and be a string")}if(Object.prototype.toString.call(segments)!=="[object Array]"){throw new Error("Invalid Argument: Segments are required.")}if(opts.rate!==undefined&&(opts.rate<0||opts.rate>1)){throw new Error("Invalid Argument: Rate must be between 0 and 1.")}if(this._startTs>this._endTs){throw new Error("Invalid Argument: end date must occur after start date.")}if(!(this._startTs<this._signupEndTs&&this._signupEndTs<=this._endTs)){throw new Error("Invalid Argument: SignupEnd must be between start and end date")}removeExpired.call(this,now);var overrides=window.bbccookies.get().match(/ckns_mandolin_setSegments=([^;]+)/);if(overrides!==null){eval("overrides = "+decodeURIComponent(RegExp.$1)+";");if(overrides[this._id]&&this._segmentSet.indexOf(overrides[this._id])==-1){throw new Error("Invalid Override: overridden segment should exist in segments array")}}if(overrides!==null&&overrides[this._id]){this._segment=overrides[this._id]}else{if((storedItem=this._store.getItem(this._id))){this._segment=storedItem.segment}else{if(this._startTs<=now&&now<this._signupEndTs&&now<=this._endTs&&this._store.isEnabled()===true){this._segment=pick(segments,this._rate);if(opts.end===undefined){this._store.setItem(this._id,{segment:this._segment})}else{this._store.setItem(this._id,{segment:this._segment,end:this._endTs})}log.call(this,"mandolin_segment")}}}log.call(this,"mandolin_view")};window.bbc.Mandolin.prototype.getSegment=function(){return this._segment};function log(actionType,params){var that=this;require(["istats-1"],function(istats){istats.log(actionType,that._id+":"+that._segment,params?params:{})})}function removeExpired(expires){var items=this._store.getItems(),expiresInt=+expires;for(var key in items){if(items[key].end!==undefined&&+items[key].end<expiresInt){this._store.removeItem(key)}}}function getLastExpirationDate(data){var winner=0,rollingExpire=daysFromNow(ROLLING_PERIOD_DAYS);for(var key in data){if(data[key].end===undefined&&rollingExpire>winner){winner=rollingExpire}else{if(+data[key].end>winner){winner=+data[key].end}}}return(winner)?new Date(winner):new Date(rollingExpire)}window.bbc.Mandolin.prototype.log=function(params){log.call(this,"mandolin_log",params)};window.bbc.Mandolin.prototype.convert=function(params){log.call(this,"mandolin_convert",params);this.convert=function(){}};function daysFromNow(n){var endDate;endDate=new Date().getTime()+(n*60*60*24)*1000;return endDate}function pick(segments,rate){var picked,min=0,max=segments.length-1;if(typeof rate==="number"&&Math.random()>rate){return null}do{picked=Math.floor(Math.random()*(max-min+1))+min}while(picked>max);return segments[picked]}window.bbc.Mandolin.Storage=function(name){validateCookieName(name);this._cookieName=name;this._isEnabled=(bbccookies.isAllowed(this._cookieName)===true&&bbccookies.cookiesEnabled()===true)};window.bbc.Mandolin.Storage.prototype.setItem=function(key,value){var storeData=this.getItems();storeData[key]=value;this.save(storeData);return value};window.bbc.Mandolin.Storage.prototype.isEnabled=function(){return this._isEnabled};window.bbc.Mandolin.Storage.prototype.getItem=function(key){var storeData=this.getItems();return storeData[key]};window.bbc.Mandolin.Storage.prototype.removeItem=function(key){var storeData=this.getItems();delete storeData[key];this.save(storeData)};window.bbc.Mandolin.Storage.prototype.getItems=function(){return deserialise(this.readCookie(this._cookieName)||"")};window.bbc.Mandolin.Storage.prototype.save=function(data){window.bbccookies.set(this._cookieName+"="+encodeURIComponent(serialise(data))+"; expires="+getLastExpirationDate(data).toUTCString()+";")};window.bbc.Mandolin.Storage.prototype.readCookie=function(name){var nameEq=name+"=",ca=window.bbccookies.get().split("; "),i,c;validateCookieName(name);for(i=0;i<ca.length;i++){c=ca[i];if(c.indexOf(nameEq)===0){return decodeURIComponent(c.substring(nameEq.length,c.length))}}return null};function serialise(o){var str="";for(var p in o){if(o.hasOwnProperty(p)){str+='"'+p+'"'+":"+(typeof o[p]==="object"?(o[p]===null?"null":"{"+serialise(o[p])+"}"):'"'+o[p].toString()+'"')+","}}return str.replace(/,\}/g,"}").replace(/,$/g,"")}function deserialise(str){var o;str="{"+str+"}";if(!validateSerialisation(str)){throw"Invalid input provided for deserialisation."}eval("o = "+str);return o}var validateSerialisation=(function(){var OBJECT_TOKEN="<Object>",ESCAPED_CHAR='"\\n\\r\\u2028\\u2029\\u000A\\u000D\\u005C',ALLOWED_CHAR="([^"+ESCAPED_CHAR+"]|\\\\["+ESCAPED_CHAR+"])",KEY='"'+ALLOWED_CHAR+'+"',VALUE='(null|"'+ALLOWED_CHAR+'*"|'+OBJECT_TOKEN+")",KEY_VALUE=KEY+":"+VALUE,KEY_VALUE_SEQUENCE="("+KEY_VALUE+",)*"+KEY_VALUE,OBJECT_LITERAL="({}|{"+KEY_VALUE_SEQUENCE+"})",objectPattern=new RegExp(OBJECT_LITERAL,"g");return function(str){if(str.indexOf(OBJECT_TOKEN)!==-1){return false}while(str.match(objectPattern)){str=str.replace(objectPattern,OBJECT_TOKEN)}return str===OBJECT_TOKEN}})();function validateCookieName(name){if(name.match(/ ,;/)){throw"Illegal name provided, must be valid in browser cookie."}}})(); /*]]>*/</script> <script type="text/javascript"> document.documentElement.className += (document.documentElement.className? ' ' : '') + 'orb-js'; fig.manager.confirm(); </script> <script src="https://web.archive.org/web/20180130113126js_/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/script/orb/api.min.js"></script> <script src="https://web.archive.org/web/20180130113126js_/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/script/orb/font.min.js"></script> <script type="text/javascript"> var blq = { environment: function() { return 'live'; } } </script> <script type="text/javascript"> /*<![CDATA[*/ function oqsSurveyManager(w, flag) { if (flag !== 'OFF' && (w.orb.fig("no") || w.orb.fig("uk"))) { w.document.write('<script type="text/javascript" src="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/script/vendor/edr.min.js"><'+'/script>'); } } oqsSurveyManager(window, 'ON'); /*]]>*/ </script>  <script type="text/javascript"> /*<![CDATA[*/ var _sf_startpt = (new Date()).getTime(); /*]]>*/ </script><style type="text/css">.bbccom_display_none{display:none;}</style><script type="text/javascript"> /*<![CDATA[*/ var bbcdotcomConfig, googletag = googletag || {}; googletag.cmd = googletag.cmd || []; var bbcdotcom = false; (function(){ if(typeof require !== 'undefined') { require({ paths:{ "bbcdotcom":"https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/bbcdotcom/1.73.0/script" } }); } })(); /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ var bbcdotcom = { adverts: { keyValues: { set: function() {} } }, advert: { write: function () {}, show: function () {}, isActive: function () { return false; }, layout: function() { return { reset: function() {} } } }, config: { init: function() {}, isActive: function() {}, setSections: function() {}, isAdsEnabled: function() {}, setAdsEnabled: function() {}, isAnalyticsEnabled: function() {}, setAnalyticsEnabled: function() {}, setAssetPrefix: function() {}, setVersion: function () {}, setJsPrefix: function() {}, setSwfPrefix: function() {}, setCssPrefix: function() {}, setConfig: function() {}, getAssetPrefix: function() {}, getJsPrefix: function () {}, getSwfPrefix: function () {}, getCssPrefix: function () {} }, survey: { init: function(){ return false; } }, data: {}, init: function() {}, objects: function(str) { return false; }, locale: { set: function() {}, get: function() {} }, setAdKeyValue: function() {}, utils: { addEvent: function() {}, addHtmlTagClass: function() {}, log: function () {} }, addLoadEvent: function() {} }; /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function(){ if (typeof orb !== 'undefined' && typeof orb.fig === 'function') { if (orb.fig('ad') && orb.fig('uk') == 0) { bbcdotcom.data = { ads: (orb.fig('ad') ? 1 : 0), stats: (orb.fig('uk') == 0 ? 1 : 0), statsProvider: orb.fig('ap') }; } } else { document.write('<script type="text/javascript" src="'+('https:' == document.location.protocol ? 'https://web.archive.org/web/20180130113126/https://www.bbc.com' : 'https://web.archive.org/web/20180130113126/http://tps.bbc.com')+'/wwscripts/data">\x3C/script>'); } })(); /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function(){ if (typeof orb === 'undefined' || typeof orb.fig !== 'function') { bbcdotcom.data = { ads: bbcdotcom.data.a, stats: bbcdotcom.data.b, statsProvider: bbcdotcom.data.c }; } if (bbcdotcom.data.ads == 1) { document.write('<script type="text/javascript" src="'+('https:' == document.location.protocol ? 'https://web.archive.org/web/20180130113126/https://www.bbc.com' : 'https://web.archive.org/web/20180130113126/http://www.bbc.com')+'/wwscripts/flag">\x3C/script>'); } })(); /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function(){ if (window.bbcdotcom && (typeof bbcdotcom.flag == 'undefined' || (typeof bbcdotcom.data.ads !== 'undefined' && bbcdotcom.flag.a != 1))) { bbcdotcom.data.ads = 0; } if (/[?|&]ads/.test(window.location.href) || /(^|; )ads=on; /.test(document.cookie) || /; ads=on(; |$)/.test(document.cookie)) { bbcdotcom.data.ads = 1; bbcdotcom.data.stats = 1; } if (window.bbcdotcom && (bbcdotcom.data.ads == 1 || bbcdotcom.data.stats == 1)) { bbcdotcom.assetPrefix = "https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/bbcdotcom/1.73.0/"; if (/(sandbox|int)(.dev)*.bbc.co*/.test(window.location.href) || /[?|&]ads-debug/.test(window.location.href) || document.cookie.indexOf('ads-debug=') !== -1) { document.write('<script type="text/javascript" src="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/bbcdotcom/1.73.0/script/dist/bbcdotcom.dev.js">\x3C/script>'); } else { document.write('<script type="text/javascript" src="https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/bbcdotcom/1.73.0/script/dist/bbcdotcom.js">\x3C/script>'); } } })(); /*]]>*/ </script><script type="text/javascript"> if (window.bbcdotcom && bbcdotcom.data.stats == 1) { document.write('<link rel="dns-prefetch" href="//web.archive.org/web/20180130113126/http://secure-us.imrworldwide.com/">'); document.write('<link rel="dns-prefetch" href="//web.archive.org/web/20180130113126/http://me-cdn.effectivemeasure.net/">'); document.write('<link rel="dns-prefetch" href="//web.archive.org/web/20180130113126/http://ssc.api.bbc.com/">'); } if (window.bbcdotcom && bbcdotcom.data.ads == 1) { document.write('<link rel="dns-prefetch" href="//web.archive.org/web/20180130113126/http://www.googletagservices.com/">'); } </script><script type="text/javascript"> if (window.bbcdotcom && bbcdotcom.data.ads == 1) { document.write('<meta name="google-site-verification" content="auTeTTwSt_KBY_4iDoR00Lwb7-qzx1IgzJy6ztaWgEI" />'); } </script><script type="text/javascript"> /*<![CDATA[*/ (function(){ if (window.bbcdotcom && (bbcdotcom.data.ads == 1 || bbcdotcom.data.stats == 1)) { bbcdotcomConfig = {"adFormat":"standard","adKeyword":"","adMode":"smart","adsEnabled":true,"appAnalyticsSections":"news>explainers","asyncEnabled":true,"disableInitialLoad":false,"advertInfoPageUrl":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/www.bbc.com\/privacy\/cookies\/international\/","advertisementText":"Advertisement","analyticsEnabled":true,"appName":"tabloid","assetPrefix":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/bbcdotcom\/1.73.0\/","customAdParams":[],"customStatsParams":[],"headline":"","id":"29240806","inAssociationWithText":"in association with","keywords":"","language":"","orbTransitional":false,"outbrainEnabled":true,"outbrainSportEnabled":true,"adsenseEnabled":true,"adsportappEnabled":true,"lotameEnabled":true,"sherlockEnabled":false,"platinumEnabled":true,"tlNewsIndexEnabled":false,"tlNewsStoryEnabled":true,"tlNewsFpEnabled":false,"winterOlympicsEnabled":false,"palEnv":"live","productName":"","sections":[],"comScoreEnabled":true,"comscoreSite":"bbc","comscoreID":"19293874","comscorePageName":"news.explainers","slots":"","sponsoredByText":"is sponsored by","adsByGoogleText":"Ads by Google","summary":"","type":"INDEX","features":{"testfeature":{"name":"testfeature","envs":["sandbox","int","test"],"on":true,"options":{},"override":null},"lxadverts":{"name":"lxadverts","envs":[],"on":true,"options":{},"override":null}},"staticBase":"\/bbcdotcom","staticHost":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk","staticVersion":"1.73.0","staticPrefix":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/bbcdotcom\/1.73.0","dataHttp":"tps.bbc.com","dataHttps":"www.bbc.com","flagHttp":"www.bbc.co.uk","flagHttps":"www.bbc.co.uk","analyticsHttp":"sa.bbc.com","analyticsHttps":"ssa.bbc.com"}; bbcdotcom.config.init(bbcdotcomConfig, bbcdotcom.data, window.location, window.document); bbcdotcom.config.setAssetPrefix("https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/bbcdotcom/1.73.0/"); bbcdotcom.config.setVersion("1.73.0"); document.write(''); document.write(''); document.write(''); if (/[?|&]ex-dp/.test(window.location.href) || document.cookie.indexOf('ex-dp=') !== -1) { bbcdotcom.utils.addHtmlTagClass('bbcdotcom-ex-dp'); } } })(); /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function() { window.bbcdotcom.head = true; }()); /*]]>*/ </script>  <script type="text/javascript"> // Globally available search context window.SEARCHBOX={"variant":"default","locale":"en","navSearchboxStaticPrefix":"//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/searchbox/1.0.0-136","searchboxAppStaticPrefix":"//web.archive.org/web/20180130113126/http://search.files.bbci.co.uk/searchbox-app/1.0.19","searchFormHtml":"<div tabindex=\"-1\" data-reactid=\".jval9y49og\" data-react-checksum=\"1886463233\"><div data-reactid=\".jval9y49og.0\"><section class=\"se-searchbox-panel\" data-reactid=\".jval9y49og.0.0\"><div class=\"se-g-wrap\" data-reactid=\".jval9y49og.0.0.0\"><div class=\"se-g-layout\" data-reactid=\".jval9y49og.0.0.0.0\"><div class=\"se-g-layout__item se-searchbox-title\" aria-hidden=\"true\" data-reactid=\".jval9y49og.0.0.0.0.0\">search</div><div class=\"se-g-layout__item se-searchbox\" data-reactid=\".jval9y49og.0.0.0.0.1\"><form accept-charset=\"utf-8\" id=\"searchboxDrawerForm\" method=\"get\" action=\"https://search.bbc.co.uk/search\" data-reactid=\".jval9y49og.0.0.0.0.1.0\"><label class=\"se-searchbox__input\" for=\"se-searchbox-input-field\" data-reactid=\".jval9y49og.0.0.0.0.1.0.0\"><span class=\"se-sr-only\" data-reactid=\".jval9y49og.0.0.0.0.1.0.0.0\">Search Term</span><input name=\"q\" type=\"text\" value=\"\" id=\"se-searchbox-input-field\" class=\"se-searchbox__input__field\" maxlength=\"512\" autocomplete=\"off\" autocorrect=\"off\" autocapitalize=\"off\" spellcheck=\"false\" tabindex=\"0\" data-reactid=\".jval9y49og.0.0.0.0.1.0.0.1\"/></label><input type=\"hidden\" name=\"scope\" value=\"\" data-reactid=\".jval9y49og.0.0.0.0.1.0.2\"/><button type=\"submit\" class=\"se-searchbox__submit\" tabindex=\"0\" data-reactid=\".jval9y49og.0.0.0.0.1.0.3\">Search</button><button type=\"button\" class=\"se-searchbox__clear se-searchbox__clear--visible\" tabindex=\"0\" data-reactid=\".jval9y49og.0.0.0.0.1.0.4\">Close</button></form></div></div></div></section><div aria-live=\"polite\" aria-atomic=\"true\" class=\"se-suggestions-container\" data-reactid=\".jval9y49og.0.1\"><section class=\"se-g-wrap\" data-reactid=\".jval9y49og.0.1.0\"></section></div></div></div>","searchScopePlaceholder":"","searchScopeParam":"","searchScopeTemplate":"","searchPlaceholderWrapperStart":"","searchPlaceholderWrapperEnd":""}; window.SEARCHBOX.suppress = false; window.SEARCHBOX.searchScope = SEARCHBOX.searchScopeTemplate.split('-')[0]; </script> <link rel="stylesheet" href="//web.archive.org/web/20180130113126cs_/http://nav.files.bbci.co.uk/searchbox/1.0.0-136/css/main.css">    <link rel="stylesheet" href="//web.archive.org/web/20180130113126cs_/http://static.bbc.co.uk/id/0.37.24/style/id-cta.css"/> <link rel="stylesheet" href="//web.archive.org/web/20180130113126cs_/http://static.bbc.co.uk/id/0.37.24/style/id-cta-v5.css"/>  <script type="text/javascript"> /* <![CDATA[ */ var map = {}; if (typeof(map['jssignals-1']) == 'undefined') { map['jssignals-1'] = 'https://web.archive.org/web/20180130113126/https://static.bbc.co.uk/frameworks/jssignals/0.3.6/modules/jssignals-1'; } require({paths: map}); /* ]]> */ </script> <script src="//web.archive.org/web/20180130113126js_/http://static.bbc.co.uk/id/0.37.24/modules/idcta/dist/idcta-1.min.js"></script> <script type="text/javascript"> (function () { if (!window.require) { throw new Error('idcta: could not find require module'); } if(typeof(map) == 'undefined') { var map = {}; } if(!!document.createElementNS && !!document.createElementNS('http://www.w3.org/2000/svg', "svg").createSVGRect) { document.documentElement.className += ' id-svg'; } var ptrt = RegExp("[\\?&]ptrt=([^&#]*)").exec(document.location.href); var ENDPOINT_URL = '//' + ((window.location.protocol == "https:") ? ('ssl.bbc.co.uk').replace("www.", "ssl.") : ('ssl.bbc.co.uk').replace("ssl.", "www.")); var ENDPOINT_CONFIG = ('/idcta/config?callback&locale=en-GB&ptrt=' + encodeURI((ptrt ? ptrt[1] : document.location.href))).replace(/\&/g, '&'); var ENDPOINT_TRANSLATIONS = '/idcta/translations?callback&locale=en-GB'; map['idapp-1'] = '//web.archive.org/web/20180130113126/http://static.bbc.co.uk/idapp/0.72.58/modules/idapp/idapp-1'; map['idcta'] = '//web.archive.org/web/20180130113126/http://static.bbc.co.uk/id/0.37.24/modules/idcta'; map['idcta/config'] = [ENDPOINT_URL + ENDPOINT_CONFIG, '//web.archive.org/web/20180130113126/http://static.bbc.co.uk/id/0.37.24/modules/idcta/fallbackConfig']; map['idcta/translations'] = [ENDPOINT_URL + ENDPOINT_TRANSLATIONS, '//web.archive.org/web/20180130113126/http://static.bbc.co.uk/id/0.37.24/modules/idcta/fallbackTranslations']; require({paths: map}); /* * Temporary code * To be removed when old id-statusbar-config is no longer supported */ define('id-statusbar-config', ['idcta/id-config'], function(conf) { return conf; }); define('idcta/id-statusbar-config', ['idcta/id-config'], function(conf) { return conf; }); })(); </script> <link rel="stylesheet" href="//web.archive.org/web/20180130113126cs_/http://mybbc.files.bbci.co.uk/notification-ui/3.8.4/css/main.min.css"/> <link type="text/css" rel="stylesheet" href="https://web.archive.org/web/20180130113126cs_/http://static.bbci.co.uk/news/1.226.02302/stylesheets/services/news/core.css">  <script id="news-loader"> if (document.getElementById("responsive-news")) { window.bbcNewsResponsive = true; } var isIE = (function() { var undef, v = 3, div = document.createElement('div'), all = div.getElementsByTagName('i'); while ( div.innerHTML = '', all[0] ); return v > 4 ? v : undef; }()); var modernDevice = 'querySelector' in document && 'localStorage' in window && 'addEventListener' in window, forceCore = document.cookie.indexOf('ckps_force_core') !== -1; window.cutsTheMustard = modernDevice && !forceCore; if (window.cutsTheMustard) { document.documentElement.className += ' ctm'; var insertPoint = document.getElementById('news-loader'), config = {"asset":{"asset_id":"29240806","asset_locator":"urn:bbc:cps:asset:29240806","asset_uri":"\/news\/explainers","original_asset_uri":null,"first_created":{"date":"2014-09-17 12:39:47","timezone_type":3,"timezone":"Europe\/London"},"first_published":{"date":"2014-09-24 17:14:17","timezone_type":3,"timezone":"Europe\/London"},"last_updated":{"date":"2018-01-30 08:28:09","timezone_type":3,"timezone":"Europe\/London"},"options":{"allowAdvertising":true},"section":{"name":"Explainers","id":"102300","uri":"\/news\/explainers","urlIdentifier":"\/news\/explainers"},"language":"en-gb","edition":"US","audience":"domestic","iStats_counter_name":"news.explainers.page","type":"IDX","curie":"asset:03425334-85d6-b09b-e050-380a4e801e3f\/desktop\/domestic"},"smpBrand":null,"staticHost":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk","environment":"live","locatorVersion":"0.46.3","pathPrefix":"\/news","staticPrefix":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/news\/1.226.02302","jsPath":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/news\/1.226.02302\/js","cssPath":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/news\/1.226.02302\/stylesheets\/services\/news","cssPostfix":"","dynamic":null,"features":{"localnews":true,"video":true,"liveeventcomponent":true,"mediaassetpage":true,"gallery":true,"rollingnews":true,"sportstories":true,"radiopromo":true,"fromothernewssites":true,"locallive":true,"weather":true},"features2":{"svg_brand":true,"waf_deprecation_notice":true,"chartbeat":true,"connected_stream":true,"connected_stream_promo":true,"nav":true,"pulse_survey":false,"local_survey":true,"correspondents":true,"blogs":true,"open_graph":true,"follow_us":true,"marketdata_markets":true,"marketdata_shares":true,"nations_pseudo_nav":true,"politics_election2015_topic_pages":true,"responsive_breaking_news":true,"live_event":true,"most_popular":true,"most_popular_tabs":true,"most_popular_by_day":false,"routing":true,"radiopromonownext":true,"config_based_layout":true,"orb":true,"map_most_watched":true,"top_stories_promo":true,"features_and_analysis":true,"section_labels":true,"index_title":true,"share_tools":true,"extracted_share_tools":true,"local_live_promo":true,"adverts":true,"adverts_async":true,"adexpert":true,"igor_geo_redirect":true,"igor_device_redirect":true,"live":true,"comscore_mmx":true,"find_local_news":true,"comments":true,"comments_enhanced":true,"browser_notify":true,"stream_grid_promo":true,"breaking_news":false,"top_stories_max_volume":true,"record_livestats":true,"contact_form":true,"channel_page":true,"portlet_global_variants":true,"suppress_lep_timezone":true,"story_sticky_player":true,"story_end_slate":true,"story_smp_preview":true,"embed_player_pid":true,"cedexis":true,"mpulse":true,"story_single_column_layout":true,"story_image_copyright_labels":true,"ovp_resolve_primary_media_vpids":false,"media_player":true,"services_bar":true,"live_v2_stream":true,"ldp_tag_augmentation":true,"map_related_topic_tags":true,"rio2016_medals":true,"embedephant-social-embeds":true,"interactive-social-embeds":true,"social-embeds":true,"amp_link":true},"configuration":{"showtimestamp":"1","showweather":"1","showsport":"1","showolympics":"1","showfeaturemain":"1","candyplatform":"EnhancedMobile","showwatchlisten":"1","showspecialreports":"","videotopiccandyid":"","showvideofeedsections":"1","showstorytopstories":"","showstoryfeaturesandanalysis":"1","showstorymostpopular":"","showgallery":"1","cms":"cps","channelpagecandyid":"10318089"},"pollingHost":"https:\/\/web.archive.org\/web\/20180130113126\/https:\/\/polling.bbc.co.uk","service":"news","locale":"en-GB","locatorHost":null,"locatorFlagPole":true,"local":{"allowLocationLookup":true},"isWorldService":false,"isChannelPage":false,"languageVariant":"","commentsHost":"https:\/\/web.archive.org\/web\/20180130113126\/https:\/\/www.bbc.co.uk","search":null,"comscoreAnalytics":null}; config.configuration['get'] = function (key) { return this[key.toLowerCase()]; }; var bootstrapUI=function(){var e=function(){if(navigator.userAgent.match(/(Android (2.0|2.1))|(Nokia)|(OSRE\/)|(Opera (Mini|Mobi))|(w(eb)?OSBrowser)|(UCWEB)|(Windows Phone)|(XBLWP)|(ZuneWP)/))return!1;if(navigator.userAgent.match(/MSIE 10.0/))return!0;var e,t=document,n=t.head||t.getElementsByTagName("head")[0],r=t.createElement("style"),s=t.implementation||{hasFeature:function(){return!1}};r.type="text/css",n.insertBefore(r,n.firstChild),e=r.sheet||r.styleSheet;var i=s.hasFeature("CSS2","")?function(t){if(!e||!t)return!1;var n=!1;try{e.insertRule(t,0),n=!/unknown/i.test(e.cssRules[0].cssText),e.deleteRule(e.cssRules.length-1)}catch(r){}return n}:function(t){return e&&t?(e.cssText=t,0!==e.cssText.length&&!/unknown/i.test(e.cssText)&&0===e.cssText.replace(/\r+|\n+/g,"").indexOf(t.split(" ")[0])):!1};return i('@font-face{ font-family:"font";src:"font.ttf"; }')}();e&&(document.getElementsByTagName("html")[0].className+=" ff"),function(){var e=document.documentElement.style;("flexBasis"in e||"WebkitFlexBasis"in e||"msFlexBasis"in e)&&(document.documentElement.className+=" flex")}();var t,n,r,s,i,a={},o=function(){var e=document.documentElement.clientWidth,n=window.innerWidth,r=n>1.5*e;t=r?e:n},u=function(e){var t=document.createElement("link");t.setAttribute("rel","stylesheet"),t.setAttribute("type","text/css"),t.setAttribute("href",n+e+r+".css"),t.setAttribute("media",i[e]),s.parentNode.insertBefore(t,s),delete i[e]},c=function(e,n,r){n&&!r&&t>=n&&u(e),r&&!n&&r>=t&&u(e),n&&r&&t>=n&&r>=t&&u(e)},l=function(e){if(a[e])return a[e];var t=e.match(/$min\-width:[\s]*([\s]*[0-9\.]+)(px|em)[\s]*$/),n=e.match(/$max\-width:[\s]*([\s]*[0-9\.]+)(px|em)[\s]*$/),r=t&&parseFloat(t[1])||null,s=n&&parseFloat(n[1])||null;return a[e]=[r,s],a[e]},f=function(){var e=0;for(var t in i)e++;return e},m=function(){f()||window.removeEventListener("resize",d,!1);for(var e in i){var t=i[e],n=l(t);c(e,n[0],n[1])}},d=function(){o(),m()},h=function(e,t){i=e,n=t.path+("/"!==t.path.substr(-1)?"/":""),r=t.postfix,s=t.insertBefore,o(),m(),window.addEventListener("resize",d,!1)};return{stylesheetLoaderInit:h}}(); var stylesheets = {"compact":"(max-width: 599px)","tablet":"(min-width: 600px)","wide":"(min-width: 1008px)"}; bootstrapUI.stylesheetLoaderInit(stylesheets, { path: 'https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/stylesheets/services/news', postfix: '', insertBefore: insertPoint }); var loadRequire = function(){ var js_paths = {"jquery-1.9":"vendor\/jquery-1\/jquery","jquery-1":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/frameworks\/jquery\/0.4.1\/sharedmodules\/jquery-1.7.2","demi-1":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/frameworks\/demi\/0.10.1\/sharedmodules\/demi-1","swfobject-2":"https:\/\/web.archive.org\/web\/20180130113126\/http:\/\/static.bbci.co.uk\/frameworks\/swfobject\/0.1.10\/sharedmodules\/swfobject-2","jquery":"vendor\/jquery-2\/jquery.min","domReady":"vendor\/require\/domReady","translation":"module\/translations\/en-GB","bump-3":"\/\/web.archive.org\/web\/20180130113126\/http:\/\/emp.bbci.co.uk\/emp\/bump-3\/bump-3"}; js_paths.navigation = 'module/nav/navManager'; requirejs.config({ baseUrl: 'https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/js', map: { 'vendor/locator': { 'module/bootstrap': 'vendor/locator/bootstrap', 'locator/stats': 'vendor/locator/stats', 'locator/locatorView': 'vendor/locator/locatorView' } }, paths: js_paths, waitSeconds: 30 }); define('config', function () { return config; }); require(["compiled\/all"], function() { require(['domReady'], function (domReady) { domReady(function () { require(["module\/dotcom\/handlerAdapter","module\/stats\/statsSubscriberAdapter","module\/alternativeJsStrategy\/controller","module\/iconLoaderAdapter","module\/polyfill\/location.origin","module\/components\/breakingNewsAdapter","module\/indexTitleAdaptor","module\/navigation\/handlerAdaptor","module\/noTouchDetectionForCss","module\/components\/commentCountAdapter","module\/components\/fauxBlockLink","module\/components\/responsiveImage","module\/components\/timestampAdaptor"], function() { require(["module\/strategiserAdaptor"]); }); }); }); }); }; loadRequire(); } else { var l = document.createElement('link'); l.href = 'https://web.archive.org/web/20180130113126/http://static.bbci.co.uk/news/1.226.02302/icons/generated/icons.fallback.css'; l.rel = 'stylesheet'; document.getElementsByTagName('head')[0].appendChild(l); } </script> <script type="text/javascript"> /*<![CDATA[*/ bbcdotcom.init({adsToDisplay:['leaderboard', 'sponsor_section', 'mpu', 'mpu_bottom', 'adsense', 'native_slice_l', 'infeed_news_index']}); /*]]>*/ </script> <noscript><link href="https://web.archive.org/web/20180130113126cs_/http://static.bbci.co.uk/news/1.226.02302/icons/generated/icons.fallback.css" rel="stylesheet"></noscript> <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=1"> </head>  <body id="asset-type-idx" class="device--feature"> <div class="direction"> <div id="bbccom_interstitial_ad" class="bbccom_display_none"></div><div id="bbccom_interstitial" class="bbccom_display_none"><script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.config.isActive('ads')) { googletag.cmd.push(function() { googletag.display('bbccom_interstitial'); }); } }()); /*]]>*/ </script></div><div id="bbccom_wallpaper_ad" class="bbccom_display_none"></div><div id="bbccom_wallpaper" class="bbccom_display_none"><script type="text/javascript"> /*<![CDATA[*/ (function() { var wallpaper; if (window.bbcdotcom && bbcdotcom.config.isActive('ads')) { if (bbcdotcom.config.isAsync()) { googletag.cmd.push(function() { googletag.display('bbccom_wallpaper'); }); } else if (typeof googletag !== "undefined" && typeof googletag.display === "function") { googletag.display("wallpaper"); } wallpaper = bbcdotcom.adverts.adRegister.getAd('wallpaper'); } }()); /*]]>*/ </script></div><script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.config.isActive('ads')) { document.write(unescape('%3Cscript id="gnlAdsEnabled" class="bbccom_display_none"%3E%3C/script%3E')); } if (window.bbcdotcom && bbcdotcom.config.isActive('analytics')) { document.write(unescape('%3Cscript id="gnlAnalyticsEnabled" class="bbccom_display_none"%3E%3C/script%3E')); } }()); /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function() { window.bbcdotcom.bodyFirst = true; }()); /*]]>*/ </script> <div id="blq-global"> <div id="blq-pre-mast"> </div> </div> <script type="text/html" id="blq-bbccookies-tmpl"><![CDATA[ <section> <div id="bbccookies" class="bbccookies-banner orb-banner-wrapper bbccookies-d"> <div id="bbccookies-prompt" class="orb-banner b-g-p b-r b-f"> <h2 class="orb-banner-title"> Cookies on the BBC website </h2> <p class="orb-banner-content" dir="ltr"> The BBC has updated its cookie policy. We use cookies to ensure that we give you the best experience on our website. This includes cookies from third party social media websites if you visit a page which contains embedded content from social media. Such third party cookies may track your use of the BBC website.<span class="bbccookies-international-message"> We and our partners also use cookies to ensure we show you advertising that is relevant to you.</span> If you continue without changing your settings, we'll assume that you are happy to receive all cookies on the BBC website. However, you can change your cookie settings at any time. </p> <ul class="orb-banner-options"> <li id="bbccookies-continue"> <button type="button" id="bbccookies-continue-button">Continue</button> </li> <li id="bbccookies-settings"> <a href="/privacy/cookies/managing/cookie-settings.html">Change settings</a> </li> <li id="bbccookies-more"><a href="/privacy/cookies/bbc">Find out more</a></li></ul> </div> </div> </section> ]]></script> <script type="text/javascript">/*<![CDATA[*/ (function(){if(bbccookies._showPrompt()){var g=document,b=g.getElementById("blq-pre-mast"),e=g.getElementById("blq-bbccookies-tmpl"),a,f;if(b&&g.createElement){a=g.createElement("div");f=e.innerHTML;f=f.replace("<"+"![CDATA[","").replace("]]"+">","");a.innerHTML=f;b.appendChild(a);blqCookieContinueButton=g.getElementById("bbccookies-continue-button");blqCookieContinueButton.onclick=function(){a.parentNode.removeChild(a);return false};bbccookies._setPolicy(bbccookies.readPolicy())}var c=g.getElementById("bbccookies");if(c&&!window.orb.fig("uk")){c.className=c.className.replace(/\bbbccookies-d\b/,"");c.className=c.className+(" bbccookies-w")}}})(); /*]]>*/</script> <noscript><p style="position: absolute; top: -999em"><img src="https://web.archive.org/web/20180130113126im_/https://sa.bbc.co.uk/bbc/bbc/s?name=news.explainers.page&ml_name=webmodule&ml_version=89&blq_js_enabled=0&blq_s=4d&blq_r=2.7&blq_v=default&blq_e=pal&cps_asset_id=29240806&page_type=Index搂ion=%2Fnews%2Fexplainers&first_pub=2014-09-17T11%3A39%3A47%2B00%3A00&last_editorial_update=2018-01-30T08%3A28%3A09%2B00%3A00&curie=03425334-85d6-b09b-e050-380a4e801e3f%2Fdesktop%2Fdomestic&for_nation=us&app_version=1.226.0&bbc_site=news&pal_route=asset&app_type=responsive&language=en-GB&pal_webapp=tabloid&prod_name=news&app_name=news" height="1" width="1" alt=""></p></noscript>  <script type="text/javascript">/*<![CDATA[*/ if (typeof bbccookies !== 'undefined' && bbccookies.isAllowed('s1')) { (function () { require(['istats-1'], function (istats) { istatsTrackingUrl = istats.getDefaultURL(); if (istats.isEnabled() && bbcFlagpoles_istats === 'ON') { sitestat(istatsTrackingUrl); } else { window.ns_pixelUrl = istatsTrackingUrl; /* used by Flash library to track */ } function sitestat(n) { var j = document, f = j.location, b = ""; if (j.cookie.indexOf("st_ux=") != -1) { var k = j.cookie.split(";"); var e = "st_ux", h = document.domain, a = "/"; if (typeof ns_ != "undefined" && typeof ns_.ux != "undefined") { e = ns_.ux.cName || e; h = ns_.ux.cDomain || h; a = ns_.ux.cPath || a } for (var g = 0, f = k.length; g < f; g++) { var m = k[g].indexOf("st_ux="); if (m != -1) { b = "&" + decodeURI(k[g].substring(m + 6)) } } bbccookies.set(e + "=; expires=" + new Date(new Date().getTime() - 60).toGMTString() + "; path=" + a + "; domain=" + h); } window.ns_pixelUrl = n; } }); })(); } else { window.istats = {enabled: false}; } /*]]>*/</script>   <header id="orb-banner" role="banner">   <div id="orb-header" class="orb-nav-pri orb-nav-pri-white b-header--white--black orb-nav-empty"> <div class="orb-nav-pri-container b-r b-g-p"> <div class="orb-nav-section orb-nav-blocks"> <a href="/web/20180130113126/http://www.bbc.com/"> <img src="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/img/bbc-blocks-dark.png" width="84" height="24" alt="BBC"/> </a> </div> <section> <div class="orb-skip-links"> <h2>Accessibility links</h2> <ul> <li><a href="#page">Skip to content</a></li> <li><a id="orb-accessibility-help" href="/web/20180130113126/http://www.bbc.com/accessibility/">Accessibility Help</a></li> </ul> </div> </section> <div id="mybbc-wrapper" class="orb-nav-section orb-nav-id orb-nav-focus"> <div id="idcta-statusbar" class="orb-nav-section orb-nav-focus"> <a id="idcta-link" href="https://web.archive.org/web/20180130113126/https://account.bbc.com/account?ptrt=http%3A%2F%2Fwww.bbc.com%2Fnews%2Fexplainers"> <span id="idcta-username">BBC iD</span> </a> </div> <script type="text/javascript"> require(['idcta/statusbar'], function(statusbar) { new statusbar.Statusbar({"id":"idcta-statusbar","publiclyCacheable":true}); }); </script> <a id="notification-link" class="js-notification-link animated three" href="#"> <span class="hidden-span">Notifications</span> <div class="notification-link--triangle"></div> <div class="notification-link--triangle"></div> <span id="not-num"></span> </a> </div> <nav role="navigation" class="orb-nav"> <div class="orb-nav-section orb-nav-links orb-nav-focus" id="orb-nav-links"> <h2>BBC navigation</h2> <ul> <li class="orb-nav-home orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/">Home</a> </li> <li class="orb-nav-homedotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/">Home</a> </li> <li class="orb-nav-news orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news">News</a> </li> <li class="orb-nav-newsdotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/news">News</a> </li> <li class="orb-nav-sport"> <a href="/web/20180130113126/http://www.bbc.com/sport/">Sport</a> </li> <li class="orb-nav-weather"> <a href="/web/20180130113126/http://www.bbc.com/weather/">Weather</a> </li> <li class="orb-nav-shop orb-w"> <a href="https://web.archive.org/web/20180130113126/http://shop.bbc.com/">Shop</a> </li> <li class="orb-nav-earthdotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/earth/">Earth</a> </li> <li class="orb-nav-travel-dotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/travel/">Travel</a> </li> <li class="orb-nav-capital orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/capital/">Capital</a> </li> <li class="orb-nav-iplayer orb-d"> <a href="/web/20180130113126/http://www.bbc.com/iplayer/">iPlayer</a> </li> <li class="orb-nav-culture orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/culture/">Culture</a> </li> <li class="orb-nav-autos orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/autos/">Autos</a> </li> <li class="orb-nav-future orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/future/">Future</a> </li> <li class="orb-nav-tv"> <a href="/web/20180130113126/http://www.bbc.com/tv/">TV</a> </li> <li class="orb-nav-radio"> <a href="/web/20180130113126/http://www.bbc.com/radio/">Radio</a> </li> <li class="orb-nav-cbbc"> <a href="/web/20180130113126/http://www.bbc.com/cbbc">CBBC</a> </li> <li class="orb-nav-cbeebies"> <a href="/web/20180130113126/http://www.bbc.com/cbeebies">CBeebies</a> </li> <li class="orb-nav-food"> <a href="/web/20180130113126/http://www.bbc.com/food/">Food</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/iwonder">iWonder</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/education">Bitesize</a> </li> <li class="orb-nav-travel orb-d"> <a href="/web/20180130113126/http://www.bbc.com/travel/">Travel</a> </li> <li class="orb-nav-music"> <a href="/web/20180130113126/http://www.bbc.com/music/">Music</a> </li> <li class="orb-nav-earth orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/earth/">Earth</a> </li> <li class="orb-nav-arts"> <a href="/web/20180130113126/http://www.bbc.com/arts/">Arts</a> </li> <li class="orb-nav-makeitdigital"> <a href="/web/20180130113126/http://www.bbc.com/makeitdigital">Make It Digital</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/taster">Taster</a> </li> <li class="orb-nav-nature orb-w"> <a href="/web/20180130113126/http://www.bbc.com/nature/">Nature</a> </li> <li class="orb-nav-local"> <a href="/web/20180130113126/http://www.bbc.com/local/">Local</a> </li> <li class="orb-nav-tomorrowsworld orb-d"> <a href="/web/20180130113126/http://www.bbc.com/tomorrowsworld">Tomorrow's World</a> </li> <li id="orb-nav-more"><a href="#orb-footer" data-alt="More">Menu<span class="orb-icon orb-icon-arrow"></span></a></li> </ul> </div> </nav> <div class="orb-nav-section orb-nav-search"> <a class="orb-search__button" href="https://web.archive.org/web/20180130113126/https://search.bbc.co.uk/search" title="Search the BBC">Search</a> <form class="b-f" id="orb-search-form" role="search" method="get" action="https://web.archive.org/web/20180130113126/https://search.bbc.co.uk/search" accept-charset="utf-8"> <div> <label for="orb-search-q">Search the BBC</label> <input id="orb-search-q" type="text" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" name="q" placeholder="Search"> <button id="orb-search-button" class="orb-search__button">Search the BBC</button> <input type="hidden" name="suggid" id="orb-search-suggid"/> </div> </form> </div> </div> <div id="orb-panels"> <script type="text/template" id="orb-panel-template"><![CDATA[ <div id="orb-panel-<%= panelname %>" class="orb-panel" aria-labelledby="orb-nav-<%= panelname %>"> <div class="orb-panel-content b-g-p b-r"> <%= panelcontent %> </div> </div> ]]></script> </div> </div> </header>  <div id="orb-modules"> <div id="site-container">  <div class="site-brand site-brand--height" role="banner" aria-label="BBC News"> <div class="site-brand-inner site-brand-inner--height"> <div class="navigation navigation--primary"> <a href="/web/20180130113126/http://www.bbc.com/news" id="brand"> <svg class="brand__svg" width="102" height="30" focusable="false" aria-hidden="true"> <image xlink:href="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/img/brand/generated/news-light.svg" src="https://web.archive.org/web/20180130113126im_/http://static.bbci.co.uk/news/1.226.02302/img/brand/generated/news-light.png" width="100%" height="100%"/> </svg> <span class="off-screen">News</span> </a> <h2 class="navigation__heading off-screen">BBC News Navigation</h2> <a href="#core-navigation" class="navigation__section navigation__section--core" data-event="header"> <div class="navigation__section--icon"> <span class="off-screen">Sections</span> </div> </a> </div> </div> <div class="navigation navigation--wide"> <ul class="navigation-wide-list" role="navigation" aria-label="BBC News" data-panel-id="js-navigation-panel-primary"> <li> <a href="/web/20180130113126/http://www.bbc.com/news" class="navigation-wide-list__link"> <span>Home</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/video_and_audio/headlines" class="navigation-wide-list__link"> <span>Video</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world" data-panel-id="js-navigation-panel-World" class="navigation-wide-list__link"> <span>World</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/us_and_canada" data-panel-id="js-navigation-panel-US___Canada" class="navigation-wide-list__link"> <span>US & Canada</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/uk" data-panel-id="js-navigation-panel-UK" class="navigation-wide-list__link"> <span>UK</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business" data-panel-id="js-navigation-panel-Business" class="navigation-wide-list__link"> <span>Business</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/technology" class="navigation-wide-list__link"> <span>Tech</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/science_and_environment" class="navigation-wide-list__link"> <span>Science</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/stories" class="navigation-wide-list__link"> <span>Stories</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/entertainment_and_arts" class="navigation-wide-list__link"> <span>Entertainment & Arts</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/health" class="navigation-wide-list__link"> <span>Health</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/in_pictures" class="navigation-wide-list__link"> <span>In Pictures</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/newsbeat" class="navigation-wide-list__link"> <span>Newsbeat</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/realitycheck" class="navigation-wide-list__link"> <span>Reality Check</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/special_reports" class="navigation-wide-list__link"> <span>Special Reports</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world_radio_and_tv" class="navigation-wide-list__link"> <span>World News TV</span> </a> </li> <li class="selected"> <a href="/web/20180130113126/http://www.bbc.com/news/explainers" class="navigation-wide-list__link navigation-arrow--open"> <span>Explainers</span> </a> <span class="off-screen">selected</span> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/the_reporters" class="navigation-wide-list__link"> <span>The Reporters</span> </a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/have_your_say" class="navigation-wide-list__link navigation-wide-list__link--last"> <span>Have Your Say</span> </a> </li> </ul> </div> </div> <div id="bbccom_leaderboard_1_2_3_4" class="bbccom_slot " aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('leaderboard', [1,2,3,4]); } })(); /*]]>*/ </script> </div> </div> <div id="breaking-news-container" data-polling-url="https://polling.bbc.co.uk/news/latest_breaking_news?audience=US" aria-live="polite"></div> <div id="page" class="configurable index reporters-explainers" data-story-id="explainers"> <div role="main"> <div class="container-width-only"> <h1 class="index-title index-title--redundant " id="comp-index-title" data-index-title-meta="{"id":"comp-index-title","type":"index-title","handler":"indexTitle","deviceGroups":null,"opts":{"alwaysVisible":false,"onFrontPage":false},"template":"index-title"}">Explainers</h1> <div id="bbccom_sponsor_section_1_2_3_4" class="bbccom_slot " aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('sponsor_section', [1,2,3,4]); } })(); /*]]>*/ </script> </div> </div> </div> <div class="container"> <div class="column--single"> <div id="comp-candy-asset-munger" class="distinct-component-group container-kestrel"> <h2 class="group-title off-screen " data-entityid="#top_stories"> Top Stories </h2> <div class="kestrel kestrel__dark faux-block-link"> <div class="kestrel-item" data-entityid="top_stories#1"> <div class="kestrel__image"> <div class="responsive-image responsive-image--16by9"> <img src="https://web.archive.org/web/20180130113126im_/https://ichef.bbci.co.uk/news/200/cpsprodpb/158DA/production/_99628288_mediaitem99628287.jpg" class="js-image-replace" alt="Man walks past Carillion building site" width="2048" height="1152"/> </div> </div> <div class="kestrel__body"> <a href="/web/20180130113126/http://www.bbc.com/news/business-42705641" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Reality Check: Are pensions on the brink?</span> </h3> </a> <p class="kestrel__summary">How many pensions are in deficit and does it matter?</p> <div class="kestrel__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1517237424" data-datetime="29 January 2018">29 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/business" class="mini-info-list__section" data-entityid="section-label">Business</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/business-42705641" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Reality Check: Are pensions on the brink?</a> </div> </div> <div class="sparrow-container sparrow-columns"> <div class="sparrow sparrow__3 sparrow__dark"> <div class="sparrow-item faux-block-link" data-entityid="top_stories#2"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/200/cpsprodpb/86E1/production/_99792543_mediaitem99792542.jpg" data-width="2048" data-height="1152" data-alt="Michel Barnier in Spain"></div>  </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/uk-politics-42860044" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Reality Check: EU lays out its transition position</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1517236792" data-datetime="29 January 2018">29 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/politics" class="mini-info-list__section" data-entityid="section-label">UK Politics</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/uk-politics-42860044" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Reality Check: EU lays out its transition position</a> </div> <div class="sparrow-item faux-block-link" data-entityid="top_stories#3"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/10CC6/production/_99660886_gettyimages-475870820.jpg" data-width="2048" data-height="1152" data-alt="Two glasses of vodka"></div>  </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/world-europe-42738511" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Reality Check: Fall in Russian alcohol consumption</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1517012620" data-datetime="27 January 2018">27 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/world/europe" class="mini-info-list__section" data-entityid="section-label">Europe</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/world-europe-42738511" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Reality Check: Fall in Russian alcohol consumption</a> </div> <div class="sparrow-item faux-block-link" data-entityid="top_stories#4"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/1A24/production/_99729660_gettyimages-486425808.jpg" data-width="2048" data-height="1152" data-alt="twenty and fifty pound notes"></div>  </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/uk-42818467" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Reality Check: Are charities allowed to return money?</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516894930" data-datetime="25 January 2018">25 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/uk" class="mini-info-list__section" data-entityid="section-label">UK</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/uk-42818467" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Reality Check: Are charities allowed to return money?</a> </div> </div> </div> </div> <div id="bbccom_mpu_1_2_3" class="bbccom_slot mpu-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('mpu', [1,2,3]); } })(); /*]]>*/ </script> </div> </div> </div> <div class="container--primary-and-secondary-columns column-clearfix"> <div class="column--primary"> <div id="comp-candy-asset-munger-2" class="distinct-component-group container-primary-slice"> <h2 class="group-title " data-entityid="#in_numbers"> In Numbers </h2> <div class="hawk faux-block-link"> <div class="hawk-item" data-entityid="top-feature-promo#1"> <div class="hawk__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/164BB/production/_95632319_mammoths_nocredit.jpg" data-width="1024" data-height="576" data-alt="Go Figure"></div>  </div> </div> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/world-asia-china-39583877" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Chinese customs officers make mammoth mammoth ivory seizure</span> </h3> </a> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/world-asia-china-39583877" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Chinese customs officers make mammoth mammoth ivory seizure</a> </div> </div> </div> <div id="bbccom_mpu_1_2_3" class="bbccom_slot mpu-ad mpu-ad-beside" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('mpu', [1,2,3]); } })(); /*]]>*/ </script> </div> </div> <div id="comp-candy-asset-munger-3" class="distinct-component-group "> <h2 class="group-title " data-entityid="#in_video_"> In Video </h2> <div class="sparrow-container sparrow-columns"> <div class="sparrow sparrow__3 sparrow__light-3"> <div class="sparrow-item faux-block-link" data-entityid="av-stories-now#1"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="responsive-image__inner-for-label"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/15CFF/production/_99734398_p05vxb81.jpg" data-width="1024" data-height="576" data-alt="Greta Gerwig"></div>  <div class="responsive-image__media-and-live-label" aria-hidden="true"> <span class="badge-icon-only badge-icon-only--video-for-image"><span class="svg-icon svg-icon--video-dark"><span class="off-screen"> Video</span></span></span> </div> </div> </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/av/entertainment-arts-42797664/five-ways-women-made-a-mark-in-oscar-nominations" class="title-link"> <span class="off-screen">Video </span> <h3 class="title-link__title"> <span class="title-link__title-text">Five ways women made a mark in Oscar nominations</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516760626" data-datetime="24 January 2018">24 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/entertainment_and_arts" class="mini-info-list__section" data-entityid="section-label">Entertainment & Arts</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/av/entertainment-arts-42797664/five-ways-women-made-a-mark-in-oscar-nominations" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Five ways women made a mark in Oscar nominations</a> </div> <div class="sparrow-item faux-block-link" data-entityid="av-stories-now#2"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="responsive-image__inner-for-label"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/831A/production/_99726533_p05vwzhl_edit.jpg" data-width="1024" data-height="576" data-alt="Five young people"></div>  <div class="responsive-image__media-and-live-label" aria-hidden="true"> <span class="badge-icon-only badge-icon-only--video-for-image"><span class="svg-icon svg-icon--video-dark"><span class="off-screen"> Video</span></span></span> </div> </div> </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/av/education-42795248/i-worry-about-not-being-good-enough" class="title-link"> <span class="off-screen">Video </span> <h3 class="title-link__title"> <span class="title-link__title-text">'I worry about not being good enough'</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516756873" data-datetime="24 January 2018">24 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/education" class="mini-info-list__section" data-entityid="section-label">Family & Education</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/av/education-42795248/i-worry-about-not-being-good-enough" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article 'I worry about not being good enough'</a> </div> <div class="sparrow-item faux-block-link" data-entityid="av-stories-now#3"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="responsive-image__inner-for-label"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/200/cpsprodpb/12F98/production/_99702777_p05vr4h1.jpg" data-width="1024" data-height="576" data-alt="A security guard show the way outside the congress centre ahead of the World Economic Forum (WEF) 2018 meeting in Davos"></div>  <div class="responsive-image__media-and-live-label" aria-hidden="true"> <span class="badge-icon-only badge-icon-only--video-for-image"><span class="svg-icon svg-icon--video-dark"><span class="off-screen"> Video</span></span></span> </div> </div> </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/av/business-42780206/davos-explained-in-90-seconds" class="title-link"> <span class="off-screen">Video </span> <h3 class="title-link__title"> <span class="title-link__title-text">Davos explained: In 90 seconds</span> </h3> </a> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516645360" data-datetime="22 January 2018">22 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/business" class="mini-info-list__section" data-entityid="section-label">Business</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/av/business-42780206/davos-explained-in-90-seconds" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Davos explained: In 90 seconds</a> </div> </div> </div> </div> <div id="bbccom_native_slice_l_1_2_3_4_5" class="bbccom_slot nativeslicel-ad nativeinfeed-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('native_slice_l', [1,2,3,4,5]); } })(); /*]]>*/ </script> </div> </div> <div id="bbccom_infeed_news_index_1_2_3_4_5" class="bbccom_slot infeednewsindex-ad nativeinfeed-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('infeed_news_index', [1,2,3,4,5]); } })(); /*]]>*/ </script> </div> </div> <div id="comp-candy-asset-munger-4" class="distinct-component-group "> <h2 class="group-title " data-entityid="#profile"> Profile </h2> <div class="merlin sparrow-container faux-block-link"> <div class="merlin-item" data-entityid="guide-content#1"> <div class="merlin__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/137D5/production/_99692897_gettyimages-686483970.jpg" data-width="976" data-height="549" data-alt="Victoria Swarovski at Canne"></div>  </div> </div> <div class="merlin__body"> <a href="/web/20180130113126/http://www.bbc.com/news/entertainment-arts-42662977" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Meet Victoria, heir to the Swarovski throne</span> </h3> </a> <p class="merlin__summary">Victoria Swarovski is one of Germany's biggest stars but says hard work, not her name, got her there.</p> <div class="merlin__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516761301" data-datetime="24 January 2018">24 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/entertainment_and_arts" class="mini-info-list__section" data-entityid="section-label">Entertainment & Arts</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/entertainment-arts-42662977" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Meet Victoria, heir to the Swarovski throne</a> </div> </div> </div> <div id="comp-candy-asset-munger-5" class="distinct-component-group "> <h2 class="group-title " data-entityid="#infographics"> Infographics </h2> <div class="sparrow-container sparrow-columns"> <div class="sparrow sparrow__2 sparrow__light"> <div class="sparrow-item faux-block-link" data-entityid="special-reports#1"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef.bbci.co.uk/news/200/cpsprodpb/1F13/production/_99655970_approval_index976-nc.png" data-width="976" data-height="549" data-alt="graphic shows comparison between obama and trump"></div>  </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/world-us-canada-38663043" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Trump's first year in seven charts</span> </h3> </a> <p class="sparrow-item__summary">Donald Trump says his administration has made "incredible progress". Do the facts back that up?</p> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1516296933" data-datetime="18 January 2018">18 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/world/us_and_canada" class="mini-info-list__section" data-entityid="section-label">US & Canada</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/world-us-canada-38663043" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Trump's first year in seven charts</a> </div> <div class="sparrow-item faux-block-link" data-entityid="special-reports#2"> <div class="sparrow-item__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/200/cpsprodpb/3E54/production/_99465951_food_consumption_1_640-nc.png" data-width="464" data-height="261" data-alt="Bread"></div>  </div> </div> <div class="sparrow-item__body"> <a href="/web/20180130113126/http://www.bbc.com/news/world-middle-east-42553516" class="title-link"> <h3 class="title-link__title"> <span class="title-link__title-text">Six charts that explain Iran protests</span> </h3> </a> <p class="sparrow-item__summary">The unrest has been fuelled by anger at mismanagement of the economy, unemployment and high prices.</p> <div class="sparrow-item__info"> <ul class="mini-info-list"> <li class="mini-info-list__item"><div class="date date--v2" data-seconds="1515059273" data-datetime="4 January 2018">4 January 2018</div></li> <li class="mini-info-list__item mini-info-list__item--section"><span class="mini-info-list__section-desc off-screen">From the section </span><a href="/web/20180130113126/http://www.bbc.com/news/world/middle_east" class="mini-info-list__section" data-entityid="section-label">Middle East</a></li> </ul> </div> </div> <a href="/web/20180130113126/http://www.bbc.com/news/world-middle-east-42553516" class="faux-block-link__overlay-link" tabindex="-1" aria-hidden="true">Full article Six charts that explain Iran protests</a> </div> </div> </div> </div> </div> <div class="column--secondary"> <div id="bbccom_mpu_4" class="bbccom_slot mpu-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('mpu', [4]); } })(); /*]]>*/ </script> </div> </div> <div id="bbccom_mpu_4" class="bbccom_slot mpu-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('mpu', [4]); } })(); /*]]>*/ </script> </div> </div> <div class="features-and-analysis" id="comp-features-and-analysis"> <h2 class="features-and-analysis__title"> From across the website </h2> <div class="features-and-analysis__stories promo-unit-spacer"> <div class="features-and-analysis__story" data-entityid="features-and-analysis#1"> <a href="/web/20180130113126/http://www.bbc.com/news/uk-42774738" class="bold-image-promo"> <div class="bold-image-promo__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/304/cpsprodpb/C8F9/production/_99694415_gettyimages-838332682.jpg" data-width="976" data-height="549" data-alt="British soldiers on a march during a military parade"></div>  </div> </div> <h3 class="bold-image-promo__title">Reality Check: What's happening to defence spending?</h3> <p class="bold-image-promo__summary">A warning from the head of the British army focuses attention on defence spending.</p> </a> </div> <div class="features-and-analysis__story" data-entityid="features-and-analysis#2"> <a href="/web/20180130113126/http://www.bbc.com/news/health-42788280" class="bold-image-promo"> <div class="bold-image-promo__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/304/cpsprodpb/14F51/production/_99714858_girlfridge.jpg" data-width="976" data-height="549" data-alt="Woman taking a cake from the fridge"></div>  </div> </div> <h3 class="bold-image-promo__title">Why stress makes you fat</h3> <p class="bold-image-promo__summary">Dr Michael Mosley explores the link between stress and over-eating - and the best stress-busting techniques.</p> </a> </div> <div class="features-and-analysis__story" data-entityid="features-and-analysis#3"> <a href="/web/20180130113126/http://www.bbc.com/news/newsbeat-42780602" class="bold-image-promo"> <div class="bold-image-promo__image"> <div class="responsive-image responsive-image--16by9"> <div class="js-delayed-image-load" data-src="https://web.archive.org/web/20180130113126oe_/https://ichef-1.bbci.co.uk/news/304/cpsprodpb/3818/production/_99706341_gettyimages-543501558.jpg" data-width="976" data-height="549" data-alt="Chrissy Chambers with her girlfriend"></div>  </div> </div> <h3 class="bold-image-promo__title">Revenge porn: What to do if you're a victim</h3> <p class="bold-image-promo__summary">More cases of revenge porn are reported in the UK every year but what can be done if it happens to you?</p> </a> </div> </div> </div> <div id="bbccom_native_1_2_3_4" class="bbccom_slot native-ad"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('native', [1,2,3,4]); } })(); /*]]>*/ </script> </div> </div> <div id="bbccom_mpu_bottom_1_2_3_4" class="bbccom_slot mpu-bottom-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('mpu_bottom', [1,2,3,4]); } })(); /*]]>*/ </script> </div> </div> <div id="bbccom_adsense_1_2_3_4" class="bbccom_slot adsense-ad" aria-hidden="true"> <div class="bbccom_advert"> <script type="text/javascript"> /*<![CDATA[*/ (function() { if (window.bbcdotcom && bbcdotcom.adverts && bbcdotcom.adverts.slotAsync) { bbcdotcom.adverts.slotAsync('adsense', [1,2,3,4]); } })(); /*]]>*/ </script> </div> </div> </div> </div> </div> </div> </div> <div id="core-navigation" class="navigation--footer"> <h2 class="navigation--footer__heading">BBC News Navigation</h2> <nav id="navigation--bottom" class="navigation navigation--bottom " role="navigation" aria-label="BBC News"> <span class="navigation-core-title">Sections</span> <ul class="navigation--bottom__toplevel"> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news" class=""> <span>Home</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/video_and_audio/headlines" class=""> <span>Video</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/world" data-panel-id="js-navigation-panel-World" class="navigation-arrow"> <span>World</span> </a> <div class="navigation-panel navigation-panel--closed js-navigation-panel-World"> <div class="navigation-panel__content"> <ul class="navigation-panel-secondary"> <li><a href="/web/20180130113126/http://www.bbc.com/news/world"><span>World Home</span></a></li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/africa"><span>Africa</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/asia"><span>Asia</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/australia"><span>Australia</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/europe"><span>Europe</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/latin_america"><span>Latin America</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/world/middle_east"><span>Middle East</span></a> </li> </ul> </div> </div> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/world/us_and_canada" data-panel-id="js-navigation-panel-US___Canada" class="navigation-arrow"> <span>US & Canada</span> </a> <div class="navigation-panel navigation-panel--closed js-navigation-panel-US___Canada"> <div class="navigation-panel__content"> <ul class="navigation-panel-secondary"> <li><a href="/web/20180130113126/http://www.bbc.com/news/world/us_and_canada"><span>US & Canada Home</span></a></li> </ul> </div> </div> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/uk" data-panel-id="js-navigation-panel-UK" class="navigation-arrow"> <span>UK</span> </a> <div class="navigation-panel navigation-panel--closed js-navigation-panel-UK"> <div class="navigation-panel__content"> <ul class="navigation-panel-secondary"> <li><a href="/web/20180130113126/http://www.bbc.com/news/uk"><span>UK Home</span></a></li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/england"><span>England</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/northern_ireland"><span>N. Ireland</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/scotland"><span>Scotland</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/wales"><span>Wales</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/politics"><span>Politics</span></a> </li> </ul> </div> </div> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/business" data-panel-id="js-navigation-panel-Business" class="navigation-arrow"> <span>Business</span> </a> <div class="navigation-panel navigation-panel--closed js-navigation-panel-Business"> <div class="navigation-panel__content"> <ul class="navigation-panel-secondary"> <li><a href="/web/20180130113126/http://www.bbc.com/news/business"><span>Business Home</span></a></li> <li> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/business/market_data"><span>Market Data</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business/markets"><span>Markets</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business-38507481"><span>Global Trade</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business/companies"><span>Companies</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business-22434141"><span>Entrepreneurship</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business-11428889"><span>Technology of Business</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business/business_of_sport"><span>Business of Sport</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business-12686570"><span>Global Education</span></a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/news/business/economy"><span>Economy</span></a> </li> </ul> </div> </div> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/technology" class=""> <span>Tech</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/science_and_environment" class=""> <span>Science</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/stories" class=""> <span>Stories</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/entertainment_and_arts" class=""> <span>Entertainment & Arts</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/health" class=""> <span>Health</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/in_pictures" class=""> <span>In Pictures</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/newsbeat" class=""> <span>Newsbeat</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/realitycheck" class=""> <span>Reality Check</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/special_reports" class=""> <span>Special Reports</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/world_radio_and_tv" class=""> <span>World News TV</span> </a> </li> <li class="selected "> <a href="/web/20180130113126/http://www.bbc.com/news/explainers" class="navigation-arrow--open"> <span>Explainers</span> </a> <span class="off-screen">selected</span> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/the_reporters" class=""> <span>The Reporters</span> </a> </li> <li class=""> <a href="/web/20180130113126/http://www.bbc.com/news/have_your_say" class=""> <span>Have Your Say</span> </a> </li> </ul> </nav> </div> <div id="comp-pattern-library-2" class="distinct-component-group "> <div id="bbc-news-services" class="blue-tit" role="navigation" aria-label="BBC News Services"> <div class="blue-tit__inner"> <h2 class="blue-tit__title">BBC News Services</h2> <ul class="blue-tit__list"> <li class="blue-tit__list-item"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/10628994" class="blue-tit__list-item-link mobile">On your mobile</a> </li> <li class="blue-tit__list-item"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/help-17655000" class="blue-tit__list-item-link connected-tv">On your connected tv</a> </li> <li class="blue-tit__list-item"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/10628323" class="blue-tit__list-item-link newsletter">Get news alerts</a> </li> <li class="blue-tit__list-item"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news/20039682" class="blue-tit__list-item-link contact-us">Contact BBC News</a> </li> </ul> </div> </div> </div> </div> </div> <div id="orb-footer" class="orb-footer orb-footer-grey b-footer--grey--white"> <div id="navp-orb-footer-promo" class="orb-footer-grey"></div> <aside role="complementary"> <div id="orb-aside" class="orb-nav-sec b-r b-g-p"> <div class="orb-footer-inner" role="navigation"> <h2 class="orb-footer-lead">Explore the BBC</h2> <div class="orb-footer-primary-links"> <ul> <li class="orb-nav-home orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/">Home</a> </li> <li class="orb-nav-homedotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/">Home</a> </li> <li class="orb-nav-news orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.co.uk/news">News</a> </li> <li class="orb-nav-newsdotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/news">News</a> </li> <li class="orb-nav-sport"> <a href="/web/20180130113126/http://www.bbc.com/sport/">Sport</a> </li> <li class="orb-nav-weather"> <a href="/web/20180130113126/http://www.bbc.com/weather/">Weather</a> </li> <li class="orb-nav-shop orb-w"> <a href="https://web.archive.org/web/20180130113126/http://shop.bbc.com/">Shop</a> </li> <li class="orb-nav-earthdotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/earth/">Earth</a> </li> <li class="orb-nav-travel-dotcom orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/travel/">Travel</a> </li> <li class="orb-nav-capital orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/capital/">Capital</a> </li> <li class="orb-nav-iplayer orb-d"> <a href="/web/20180130113126/http://www.bbc.com/iplayer/">iPlayer</a> </li> <li class="orb-nav-culture orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/culture/">Culture</a> </li> <li class="orb-nav-autos orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/autos/">Autos</a> </li> <li class="orb-nav-future orb-w"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/future/">Future</a> </li> <li class="orb-nav-tv"> <a href="/web/20180130113126/http://www.bbc.com/tv/">TV</a> </li> <li class="orb-nav-radio"> <a href="/web/20180130113126/http://www.bbc.com/radio/">Radio</a> </li> <li class="orb-nav-cbbc"> <a href="/web/20180130113126/http://www.bbc.com/cbbc">CBBC</a> </li> <li class="orb-nav-cbeebies"> <a href="/web/20180130113126/http://www.bbc.com/cbeebies">CBeebies</a> </li> <li class="orb-nav-food"> <a href="/web/20180130113126/http://www.bbc.com/food/">Food</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/iwonder">iWonder</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/education">Bitesize</a> </li> <li class="orb-nav-travel orb-d"> <a href="/web/20180130113126/http://www.bbc.com/travel/">Travel</a> </li> <li class="orb-nav-music"> <a href="/web/20180130113126/http://www.bbc.com/music/">Music</a> </li> <li class="orb-nav-earth orb-d"> <a href="https://web.archive.org/web/20180130113126/http://www.bbc.com/earth/">Earth</a> </li> <li class="orb-nav-arts"> <a href="/web/20180130113126/http://www.bbc.com/arts/">Arts</a> </li> <li class="orb-nav-makeitdigital"> <a href="/web/20180130113126/http://www.bbc.com/makeitdigital">Make It Digital</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/taster">Taster</a> </li> <li class="orb-nav-nature orb-w"> <a href="/web/20180130113126/http://www.bbc.com/nature/">Nature</a> </li> <li class="orb-nav-local"> <a href="/web/20180130113126/http://www.bbc.com/local/">Local</a> </li> <li class="orb-nav-tomorrowsworld orb-d"> <a href="/web/20180130113126/http://www.bbc.com/tomorrowsworld">Tomorrow's World</a> </li> </ul> </div> </div> </div> </aside> <footer role="contentinfo"> <div id="orb-contentinfo" class="orb-nav-sec b-r b-g-p"> <div class="orb-footer-inner"> <ul> <li> <a href="/web/20180130113126/http://www.bbc.com/terms/">Terms of Use</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/aboutthebbc/">About the BBC</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/privacy/">Privacy Policy</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/privacy/cookies/about">Cookies</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/accessibility/">Accessibility Help</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/guidance/">Parental Guidance</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/contact/">Contact the BBC</a> </li> <li> <a href="/web/20180130113126/http://www.bbc.com/bbcnewsletter">Get Personalised Newsletters</a> </li> <li class=" orb-w"> <a href="https://web.archive.org/web/20180130113126/http://advertising.bbcworldwide.com/">Advertise with us</a> </li> <li class=" orb-w"> <a href="/web/20180130113126/http://www.bbc.com/privacy/cookies/international/">Ad choices</a> </li> </ul> <small> <span class="orb-hilight">Copyright © 2018 BBC.</span> The BBC is not responsible for the content of external sites. <a href="/web/20180130113126/http://www.bbc.com/help/web/links/" class="orb-hilight">Read about our approach to external linking.</a> </small> </div> </div> </footer> </div> <div class="bbccom_display_none"><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && window.bbcdotcom.analytics && bbcdotcom.config && !bbcdotcom.config.isSportApp()) { bbcdotcom.analytics.page(); } /*]]>*/ </script><noscript><img src="//web.archive.org/web/20180130113126im_/http://ssc.api.bbc.com/?c1=2&c2=19293874&ns_site=bbc&name=news.explainers" height="1" width="1" alt=""></noscript><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && bbcdotcom.currencyProviders) { bbcdotcom.currencyProviders.write(); } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && bbcdotcom.currencyProviders) { bbcdotcom.currencyProviders.postWrite(); } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && bbcdotcom.data && bbcdotcom.data.stats && bbcdotcom.data.stats == 1 && bbcdotcom.config && bbcdotcom.config.isLotameEnabled && bbcdotcom.config.isLotameEnabled() && bbcdotcom.lotame){ bbcdotcom.lotame.write(); } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ /** * ASYNC waits to make any gpt requests until the bottom of the page */ if ( window.bbcdotcom && bbcdotcom.data && bbcdotcom.data.ads && bbcdotcom.data.ads == 1 && bbcdotcom.config && bbcdotcom.config.isAsync && bbcdotcom.config.isAsync() ) { (function () { var gads = document.createElement('script'); gads.async = true; gads.type = 'text/javascript'; var useSSL = 'https:' == document.location.protocol; gads.src = (useSSL ? 'https:' : 'http:') + '//web.archive.org/web/20180130113126/http://www.googletagservices.com/tag/js/gpt.js'; var node = document.getElementsByTagName('script')[0]; node.parentNode.insertBefore(gads, node); })(); } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && bbcdotcom.data && bbcdotcom.data.stats && bbcdotcom.data.stats === 1 && bbcdotcom.utils && window.location.pathname === '/' && window.bbccookies && bbccookies.readPolicy('performance') ) { var wwhpEdition = bbcdotcom.utils.getMetaPropertyContent('wwhp-edition'); var _sf_async_config={}; /** CONFIGURATION START **/ _sf_async_config.uid = 50924; _sf_async_config.domain = "bbc.co.uk"; _sf_async_config.title = "Homepage"+(wwhpEdition !== '' ? ' - '+wwhpEdition : ''); _sf_async_config.sections = "Homepage"+(wwhpEdition !== '' ? ', Homepage - '+wwhpEdition : ''); _sf_async_config.region = wwhpEdition; _sf_async_config.path = "/"+(wwhpEdition !== '' ? '?'+wwhpEdition : ''); /** CONFIGURATION END **/ (function(){ function loadChartbeat() { window._sf_endpt=(new Date()).getTime(); var e = document.createElement("script"); e.setAttribute("language", "javascript"); e.setAttribute("type", "text/javascript"); e.setAttribute('src', '//web.archive.org/web/20180130113126/http://static.chartbeat.com/js/chartbeat.js'); document.body.appendChild(e); } var oldonload = window.onload; window.onload = (typeof window.onload != "function") ? loadChartbeat : function() { oldonload(); loadChartbeat(); }; })(); } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ if (window.bbcdotcom && bbcdotcom.data && bbcdotcom.data.stats == 1 ) { var js_loaded=false, percent; if (window.bbcdotcom && bbcdotcom.config && bbcdotcom.config.isSherlockEnabled()) { document.write('<script src="//web.archive.org/web/20180130113126/http://stag.mdotlabs.com/ads.js">\x3C/script>'); if(document.location.protocol === "http:"){ document.write('<script src="//web.archive.org/web/20180130113126/http://stag.mdotlabs.com/sherlock.php?clientID=19293874">\x3C/script>'); } else { document.write('<script src="//web.archive.org/web/20180130113126/http://stag.mdotlabs.com/sherlock.php?clientID=19293874&sec=1">\x3C/script>'); } } } /*]]>*/ </script><script type="text/javascript"> /*<![CDATA[*/ (function() { window.bbcdotcom.bodyLast = true; }()); /*]]>*/ </script></div> <script type="text/javascript" id="orb-js-script" data-assetpath="http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/" src="https://web.archive.org/web/20180130113126js_/http://static.bbci.co.uk/frameworks/barlesque/3.21.31/orb/4/script/orb.min.js"></script> <script type="text/javascript"> (function() { 'use strict'; var promoManager = { url: '', promoLoaded: false, makeUrl: function (theme, site, win) { var loc = win? win.location : window.location, proto = loc.protocol, host = loc.host, url = proto + '//' + ((proto.match(/s:/i) && !host.match(/^www\.(int|test)\./i))? 'ssl.' : 'www.'), themes = ['light', 'dark']; if ( host.match(/^(?:www|ssl|m)\.(int|test|stage|live)\.bbc\./i) ) { url += RegExp.$1 + '.'; } else if ( host.match(/^pal\.sandbox\./i) ) { url += 'test.'; } theme = themes[ +(theme === themes[0]) ]; return url + 'bbc.co.uk/navpromo/card/' + site + '/' + theme; }, init: function(node) { var disabledByCookie = (document.cookie.indexOf('ckns_orb_nopromo=1') > -1), that = this; if (window.promomanagerOverride) { for (var p in promomanagerOverride) { that[p] = promomanagerOverride[p]; } } if ( window.orb.fig('uk') && !disabledByCookie ) { require(['orb/async/_footerpromo', 'istats-1'], function(promo, istats) { var virtualSite = istats.getSite() || 'default'; that.url = (window.promomanagerOverride || that).makeUrl('light', virtualSite); if (that.url) { promo.load(that.url, node, { onSuccess: function(e) { if(e.status === 'success') { node.parentNode.className = node.parentNode.className + ' orb-footer-promo-loaded'; promoManager.promoLoaded = true; promoManager.event('promo-loaded').fire(e); } }, onError: function() { istats.log('error', 'orb-footer-promo-failed'); bbccookies.set('ckns_orb_nopromo=1; expires=' + new Date(new Date().getTime() + 1000 * 60 * 10).toGMTString() + ';path=/;'); } }); } }); } } }; define('orb/promomanager', ['orb/lib/_event'], function (event) { event.mixin(promoManager); return promoManager; }); require(['orb/promomanager'], function (promoManager) { promoManager.init(document.getElementById('navp-orb-footer-promo')); }) })(); </script> <script type="text/javascript"> require.config({ paths: { "mybbc/templates": '//web.archive.org/web/20180130113126/http://mybbc.files.bbci.co.uk/notification-ui/3.8.4/templates', "mybbc/notifications": '//web.archive.org/web/20180130113126/http://mybbc.files.bbci.co.uk/notification-ui/3.8.4/js' } }); require(['mybbc/notifications/NotificationsMain', 'idcta/idcta-1'], function (NotificationsMain, idcta) { var loadNotifications = function (fig) { if (fig.geo.isUK()) { NotificationsMain.run(idcta, '//web.archive.org/web/20180130113126/http://mybbc.files.bbci.co.uk/notification-ui/3.8.4/'); } }; var orbFig = window.orb.fig; if (typeof orbFig.load === 'function') { // Use new async API from Orbit orbFig.load(loadNotifications, loadNotifications); } else { // Use old sync-only API from PAL orbfig project loadNotifications(orbFig); } }); </script> <script type="text/javascript"> if (typeof require !== 'undefined') { require(['istats-1'], function(istats){ istats.track('external', { region: document.getElementsByTagName('body')[0] }); istats.track('download', { region: document.getElementsByTagName('body')[0] }); }); } </script> <script type="text/javascript"> if (window.SEARCHBOX.suppress === false && window.SEARCHBOX.locale && /^en-?.*?/.test(window.SEARCHBOX.locale)) { require.config({ paths: { "search/searchbox": window.SEARCHBOX.searchboxAppStaticPrefix, "disco-layer": "//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/discovery-layer/0.0.1-117.f862de7/app" } }); require(['search/searchbox/searchboxDrawer'], function (SearchboxDrawer) { SearchboxDrawer.run(window.SEARCHBOX); }); var loadDiscoveryLayer = function (fig) { if (fig.geo.isUK()) { require(['disco-layer'], function (discoLayer) { discoLayer.run("//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/discovery-layer/content/", "//web.archive.org/web/20180130113126/http://nav.files.bbci.co.uk/discovery-layer/0.0.1-117.f862de7/main.css"); }); } }; var orbFig = window.orb.fig; if (typeof orbFig.load === 'function') { // Use new async API from Orbit orbFig.load(loadDiscoveryLayer); } else { // Use old sync-only API from PAL orbfig project loadDiscoveryLayer(orbFig); } } </script> <script type="text/javascript">require(["megavolt-client","istats-1","orb/cookies"],function(t,e,i){function o(){return"true"===l&&a&&t&&"function"==typeof t.getMVTIStatsLabels}function n(){!c&&o()?setTimeout(function(){e.invoke()},"500"):e.invoke()}var s=navigator.userAgent.toLowerCase(),a=!(s.indexOf("msie")>-1)||parseInt(s.split("msie")[1],10)>10,c=!1,l="true";if(i.isAllowed("s1"))try{if(o()&&t.getMVTIStatsLabels(function(t){e.addLabels(t),c=!0}),!require.s.contexts._.config.paths.idcta)return void n();require(["idcta/idcta-1"],function(t){t&&"function"==typeof t.getIStatsLabels&&e.addLabels(t.getIStatsLabels()),n()},function(t){throw t})}catch(t){console&&"function"==typeof console.log&&console.log("an exception occurred while adding idcta labels to istats, invoking istats without them",t),n()}});</script> </div> <script> window.old_onload = window.onload; window.onload = function() { if(window.old_onload) { window.old_onload(); } window.loaded = true; }; </script>  <script type="text/javascript"> /** CONFIGURATION START **/ var _sf_async_config = {}; _sf_async_config.uid = "50924"; _sf_async_config.domain = "www.bbc.co.uk"; _sf_async_config.sections = "News, News - explainers, News - IDX, News - explainers - IDX, News - unknown";  _sf_async_config.path = "bbc.co.uk/news/explainers/?us"; _sf_async_config.title = "BBC News - Explainers - domestic"; (function() { var noCookies = true; var cookiePrefix = '_chartbeat'; if ("object" === typeof bbccookies && typeof bbccookies.readPolicy == 'function') { noCookies = !bbccookies.readPolicy().performance; } if (noCookies && document.cookie.indexOf(cookiePrefix) !== -1) { //Find and remove cookies whose names begin with '_chartbeat' var cookieSplit = document.cookie.split(';'); var cookieLength = cookieSplit.length; while (cookieLength--) { var cookie = cookieSplit[cookieLength].replace(/^\s+|\s+$/g, ''); var cookieName = cookie.split('=')[0]; if (cookieName.indexOf(cookiePrefix) === 0) { document.cookie = cookieName + '=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/;'; } } } _sf_async_config.noCookies = noCookies; }()); /** CONFIGURATION END **/ (function(){ function loadChartbeat() { window._sf_endpt=(new Date()).getTime(); var e = document.createElement("script"); e.setAttribute("language", "javascript"); e.setAttribute("type", "text/javascript"); e.setAttribute('src', '//web.archive.org/web/20180130113126/http://static.chartbeat.com/js/chartbeat.js'); document.body.appendChild(e); } var oldonload = window.onload; window.onload = (typeof window.onload != "function") ? loadChartbeat : function() { oldonload(); loadChartbeat(); }; }()); </script>   <script> (function(){ window.bbcnewsperformance = {}; var perf = window.performance; function firstScrollTimer() { document.removeEventListener('scroll', firstScrollTimer); perf.mark('firstScroll'); perf.measure('scrolltime', 'firstScroll'); var timing = perf.getEntriesByName('scrolltime'); bbcnewsperformance.firstScrollTime = timing[0].startTime; } if (perf && perf.mark && perf.measure) { document.addEventListener('scroll', firstScrollTimer); } var random = Math.random(); var rate = 0.25; var throttle = 0.02; var forceMpulse = window.location.href.match(/force_mpulse/); if (rate && throttle && (random < (rate * throttle)) || forceMpulse) { if(window.BOOMR && window.BOOMR.version){return;} var dom,doc,where,iframe = document.createElement('iframe'),win = window; function boomerangSaveLoadTime(e) { win.BOOMR_onload=(e && e.timeStamp) || new Date().getTime(); } if (win.addEventListener) { win.addEventListener("load", boomerangSaveLoadTime, false); } else if (win.attachEvent) { win.attachEvent("onload", boomerangSaveLoadTime); } iframe.src = "javascript:false"; iframe.title = ""; iframe.role="presentation"; (iframe.frameElement || iframe).style.cssText = "width:0;height:0;border:0;display:none;"; where = document.getElementsByTagName('script')[0]; where.parentNode.insertBefore(iframe, where); try { doc = iframe.contentWindow.document; } catch(e) { dom = document.domain; iframe.src="javascript:var d=document.open();d.domain='"+dom+"';void(0);"; doc = iframe.contentWindow.document; } doc.open()._l = function() { var js = this.createElement("script"); if(dom) this.domain = dom; js.id = "boomr-if-as"; js.src = '//web.archive.org/web/20180130113126/http://c.go-mpulse.net/boomerang/' + '86ZLR-T78UG-6FNFN-UVDPZ-VZFWR'; BOOMR_lstart=new Date().getTime(); this.body.appendChild(js); }; doc.write('<body onload="document._l();">'); doc.close(); } })(); </script>  </body> </html>

CINXE.COM

Explainers - BBC News