SSRS count row values

Hi,

I have a row group on my report, and I want to count all rows where the value is > 0. The sample is per teh below:

The row I am interested in the SS totals. In the example above, 17 is the number of different users , 11 should be the count of all stores with values > 0. The 0.65 is a percentage, i.e 11/17.

I am using an expression in my matrix row to fine total stores with sticks (=countdistinct(Fields!avail_stick.Value))

Please assist