Chart based on Formula in Group Footer

[suganr]

Hi
I have a formula in the group footer that calculates the sum of a running total field(sum1). I am trying to have a chart that plots the following data - on change of field grouped by(time) show change of the formula(sum1) in the group footer.

I am having this problem - the graph show the sum of the fields till the first record in the group and not the last record - i,e time vs sum1 till the first record of the group. How can I overcome this?

I would appreciate any feedback on this.

Thanks

Sugan