Wrong Grand Total value

Hello

I know this is a very hot topic in this forum, but I have read many threads and none helps me.

I am trying to work a KPI throughout the year. I have my date worked in query and I have a measure calculated in pivot. My data is super simple. Basically, it is "SI" overall the 100% per analyst. In this example, in may he accomplished 21 out of 33, which is 63,64%. KPI 85%

My measure: %Mensual:=[SI]/COUNT([Cumplimiento]), where "Cumplimiento" is the column where SI and NO reside

So far, this works as it is, but when I try to lay out the annual view, I can't get the grand total to show the right data and the annual KPI is wrong

I tried creating a new measure, but it will show it for every month and it is not what I want.

Is there another way to solve it?

I am only working on excel now, I was asked to not do it in BI.

Thank you in advance!