Average in Subtotals for Pivot Table

[efarkouh]

It's a simple problem and I tried to search it but could not find anything that worked or that I understood very well.

I have a calculated field whose format is a percentage. I would like the subtotal to show me the average percentage. If I have 20%, 40%, and 60%, and Excel tells me that the average is 40%, that's useful, but if it shows me 120% (because it summed percentages), it's not very useful at all. Is there any way to show the average in the subtotals rather than the sum?

Just as a note, I've tried to change the "Value Field Settings" to "Average" and that did not change a thing, it stayed summed up.