I am trying to achieve the sum of exactly previous 13 rows for Achievement. My data is structured on weeks, quarters and fy. For eg on week 9 of any quarter i want the whole sum of previous weeks in that quarter + the previous ones from prior quarter until there are 13 weeks.
w9=sum(week9->week1 current quarter)+sum(week10->week13 previous quarter).
w10=sum(week10->week1 current quarter)+sum(week11->week13 previous quarter)
w1=sum(week1 current quarter )+sum(week2->week13 previous quarter)
Any ideas how it can be achieved?
There is also an example in the attached xls file.
I would like to give the credit to you and mark this as Correct Answer but i can't because there is a small mistake. Please remove "-" from the front of 12 and then is correct.
