title: Formatting percentages using toLocaleString causes value to be multiplied by 100
body: <p>I've been racking my head as to trying to understand why when using <code>Number.prototype.toLocaleString</code>, it is multiplying my number by 100. </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var num = 5;
  alert(num + ' vs ' + num.toLocaleString('en-GB', { style: 'percent' }));</code></pre>
  </div>
  </div>
  </p>
  
  <p>Reading through all the reference guides, I have not seen anything that suggests it should be. </p>
  
  <p>Have I completely missed the point?</p>