private float drawVerticalBar(float left, BarChartItem item)
{
var barValue = (((float)item.Value * 100f / (float)_maxValueItem.Value)) * (ChartHeight - BottomMargin - Margin - Margin) / 100f;
_template.SetColorStroke(VerticalBarBorderColor);
_template.SetLineWidth(VerticalBarBorderLineWidth);
_template.SetColorFill(item.Color);
_template.Rectangle(left, Margin + BottomMargin, BarWidth, barValue);
_template.FillStroke();
return barValue;
}