Pie Chart Problem

Hello,

I have included a pie chart in my report. The data for the pie chart comes from a table that looks like this:

Days RfsType
----------------------------------------------------- -------
171.0 DEVBP
103.5 DEVIN
2.0 DEVMA
178.6800000667572 BUG
0.0 DEVLE
18.5 CLQT

On the pie chart, I need to combine the DEVMA and CLQT values (i.e. add the Days together to get the value), and treat them as a single pie slice. Right now it is treating both as individual slices since I am grouping on RfsType.

How can I fix this

Thx.