I understood that he was asking if the t-shirt sold count will be a week-to-week sum or always and only the shirts sold in the current week.
Example
John Doe week 1 sold $ 6,000 in t-shirts, week 2 sold $ 10,000 in t-shirts,
will that $ 10,000 refer only to week 2 or will it be the result of $ 6000 of week 1 + $ 4000 of week 2?
I believe they will always and only refer to the current week .. otherwise it would create a lot of confusion ..