Exception Aggregation for %age field

Hi Experts,

I have a percentage field as a key field with another key field for amount. I have to build a report with MTD and YTD numbers. I need exception aggregation for %age key field. I tried the Average (values not equal to zero) but this one doesnt give me the expected numbers.

Has any one built a solution where he/she has used %age fields and defined any particular exception aggregation for it to work.

Regards

Bhawick