title: highchart total in tooltip
body: <p>i am using this code to display a shared tooltip:</p>
  
  <pre><code>tooltip: {
      crosshairs: true,
      shared: true,
      headerFormat: 'KW {point.key}&lt;table&gt;',
      pointFormat: '&lt;tr&gt;&lt;td style=\"color: {series.color}\"&gt;{series.name}: &lt;b&gt;&lt;/td&gt;&lt;td&gt;{point.y} USD&lt;/b&gt;&lt;/td&gt;&lt;/tr&gt;',
      useHTML: true,
      footerFormat: '&lt;/table&gt;',
      valueDecimals: 2
  },
  </code></pre>
  
  <p>Now i like to add all point.y values as a total value of the point. But how can i loop the point.y of each series to calculate the total value?</p>