Thank you but I want to create a memory variable which sums up the total sales categories.
example:

sales cat 1 521.00 1.57%
sales cat 2 6525.00 19.66%
sales cat 3 3625.00 10.92%
sales cat 4 22512.00 67.84%

Total Sales 33183.00 100.00%

expense cat 1 2252.00 6.79%
expense cat 2 2525.00 7.61%
expense cat 3 3987.50 12.02%
expense cat 4 2365.52 7.13%
Total expenses 11130.02 33.54%

Net Profit (Loss) 22052.98 66.46%

In this case, the total for all sales is 33183.00. That amount will become the denomenator for all the ratio calculations in the report.

521.00 / 33183.00 = 1.57%
33183.00 / 33183.00 = 100.00%
3987.50 / 33183.00 = 12.02%
22052.98 / 33183.00 = 66.46%
and so on.

I believe the calculation must be made in an additional detail band, but I am having trouble obtaining my desired result.

GSD