Feel you pain - the process is more complex that it first appears
see the attached
the REd tab is the summary -
the sequence is to rank the customers by sales, determine the running sales and identify the divisions - then comeback and aggregate the customers into the appropriate group (in my case quintile)
the detail includes all customers and the summary collapses the groups - counts the customers in each and determines the total - because ranking gets into table calculations the process is a bit confusing
Let me know if you have additional questions
If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution. Thank you.