code: function () {
  		var i,
  			total = 0,
  			points,
  			len,
  			point,
  			ignoreHiddenPoint = this.options.ignoreHiddenPoint;
  
  		Series.prototype.generatePoints.call(this);
  
  		// Populate local vars
  		points = this.points;
  		len = points.length;
  		
  		// Get the total sum
  		for (i = 0; i < len; i++) {
  			point = points[i];
  			total += (ignoreHiddenPoint && !point.visible) ? 0 : point.y;
  		}
  		this.total = total;
  
  		// Set each point's properties
  		for (i = 0; i < len; i++) {
  			point = points[i];
  			point.percentage = total > 0 ? (point.y / total) * 100 : 0;
  			point.total = total;
  		}
  		
  	}
docs: Extend the generatePoints method by adding total and percentage properties to each point