Difficulties charting trends

[cfsutter]

I'm trying to create a trend analysis of average days open for tickets by month/priority in rolling 13 mos line chart. I have no problem getting the data itself and easily calculated the cumulative average per month with running totals. However, I quickly found that I cannot use a formula in a chart which uses two running totals for the calculation. The calculation I used is #RT total days open/#RT open ticket count. When I use this calculation the formula does not appear to be an option when I go to select the field to use for "Show Values". Obviously if I am going to trend average days open by month over a 13 mos period I need to be able to show the values for the average number of days.

Since I couldn't use the formula that calculated off the running totals I created a set of formulas using variables to calculate a running total. Again I had no problem getting the correct data, but I've run into a new problem. I can use the new formulas in the Show Values section but the report only shows the average value for the last of the 13 mos. While the correct data is being displayed in the report there must be an issue with the formula if the chart is not displaying all the months.

My formulas are below.

@Running Total Days Aging - placed in the Group #1 Header - @Month

WhilePrintingRecords;
NumberVar Aging;

Aging := Aging + {@Days Aging calculation};


@AgingDisplay - placed in the Group #1 Footer - @Month

WhilePrintingRecords;
NumberVar Aging;


The chart itself is placed in the Report Header.

I'd really appreciate some feedback on this. I feel like I am overlooking something obvious but am just not seeing it.

Thank you!