Last N Months Measures

Hello!

I have a Measure called NPS Score. This score is calculate liked this:

NPS Score =
var PromoterDetractor =
CALCULATE(Detail[Total Surveys],FILTER(Detail,Detail[Recommend Rating] = "Promoter")) - CALCULATE(Detail[Total Surveys],FILTER(Detail,Detail[Recommend Rating] = "Detractor"))

var Percentage =
divide(100,Detail[Total Surveys])

RETURN
PromoterDetractor * Percentage

I would like to have a table chart that looks like this:

I am struggling figuring out how to do this. I would like the NPS score as of what whatever the N filter would indicate. How do you create a Measure for that? Thank you!