WAD pie chart issue

Hello All,

         We are using dashboard in which we are using PIE chart to display the percentage sales for each customer group.

         Problem I am facing is whenever the sales value for all the four customer groups is zero PIE chart is showing the percentages

         as 25. as it is equally divided as 25% for each.

         Is it possible to show the chart without these percentages whenever all the four customer group sales is zero.

         Please help me as soon as possible.

         Find the Pie chart as shown in the attached screen shot.

Regards

Anwar