' },
  xAxis: {
    categories: [
      pageStats.group1.htmlName,
      pageStats.group2.htmlName,
      pageStats.group3.htmlName,
      pageStats.group4.htmlName
    ]
  },
  yAxis: {
    title: { text: 'Number of Requests' },
    reversedStacks: false
  },
  tooltip: {
    formatter: function() {
      var s;
      if (this.point.name) { // the pie chart
        s = ''+ this.point.name +': '+ this.y +'% requests';
      } else {
        s = ''+ this.y + ' requests';
      }
      return s;
    }
  },
  