Customer Count for 80% of Sales

[#1]

Hi,

I'm trying to create a text box that will show count of customers that make 80% of sales. In another words how many largest customers produce 80% of total sales. I researched discussions on this topic but couldn't find a solution that will show this number in a text box. Does anyone have a solution for this?

Thanks!

[Gysbert_Wassenaar]

See this discussion. Especially the posts by John Witherspoon.