How to calculate cumulative training hours per staff

[Bob07]

Hi everyone,

I need your help. I have a data as shown below. I have calculated the sum of training hours per staff for each region. However, I want to calculate the number of staff who have done a total of 8 hours above, 16 hours above, 24 hours above, and 32 hours above. I will then divide these numbers by the headcount for that region as shown below. My values for single  quarter selection are correct, but wrong when I select another quarter. 

[kaushi2020]

RangeSum(Above(Sum(DISTINCT {<Year=, Month=, Day = >} [Training Hours]), 0, RowNo())))