Hi,
I have a file with cohorts of customers (years), months since the customer joined with sales per month.
I need to be able to sum cumulative sales per month for each cohort of customers and then get an average cumulative sales per month for the customers in the cohort
File attached (which explains it a bit better!)
For cumulative sales I have used rangesum(above(sum(sales), 0 , RowNo()))
But I need to count the customer per month (for each year this will be the same per month)
Please help!
Michelle
