Running total for formula field in a group

Yahoo Archive
1
I'm working on a sales report that looks at sales for each sales rep compared to their quota for the month. I've gotten the subtotals to show each month's Sales Orders and I got it to show the monthly sales quota by do an average summary of my formula field {SRepQHed.TotalQuotaAmt}/12. I want the running total to take the number in each monthly group and do a running total throughout the year. So if the calculated montly quota was 1,000 the running total would be 1,000 then 2,000 etc. Currently it doesn't do that. Any ideas or is this not possible?

I used this example to write my formulas
Formula 1
This formula resets the variable to 0 each time the month changes. WhilePrintingRecords;
CurrencyVar SubTotal := 0

Formula 2
This formula calculates the sub totals and grand total. WhilePrintingRecords;
CurrencyVar SubTotal;
CurrencyVar GrandTotal;
GrandTotal := GrandTotal + {Customer.Last Year's Sales};
SubTotal := SubTotal + {Customer.Last Year's Sales}

Formula 3
This formula displays the final value of the SubTotal variable for each Region.
WhilePrintingRecords;
CurrencyVar SubTotal;
SubTotal

Formula 4
This formula displays the grand total of all the records in the report.
WhilePrintingRecords;
CurrencyVar GrandTotal;
GrandTotal