Calculate attrition

Suppose I have a list with clients and the months they have been onboard. The clients are either active or inactive, and I want to make a chart going from 0 months to Max months, where at month i I will have the percentile of clients that "made it" to i months without quitting. So far, I have been using R and 12 measures* to produce this chart. 

Note that this chart can easily be made with an auxiliary table, but then I can not filter on my data in the report.

Anyone else stumbled across something like that?

Last note- I recently saw the whatif trick, which allows to perform * with a parameter, but this can not be transfered to R, sadly.


*The measures are of the sort 
i month attrition = CALCULATE(COUNTROWS('Gifts'), FILTER('Gifts','Gifts'[months onboard]>=i)) / CALCULATE(COUNTROWS('Gifts'), FILTER('Gifts',not ('Gifts'[IsActive]= TRUE() && ('Gifts'[Months onboard]<i))