Kpi problem - need help to find correct formula

[#1]

Hi Everybody,

I am facing some problem getting the KPI I want.I need to find the correct formula to get the following KPI:

What is the area with an average yield above 90 ?

Here is my data sample:

By sorting with the highest yield on the top in a table, and then calculating the cumul yield and area, I find easily the correct answer, which is in this case 124.6.

Does anyone know how to get this value directly in a KPI ?

Thank you for your help,

Regards,

Tanguy

[#2]

I does not work, when I add some data, there is no change