Rolling Week number - end of year

[PCRIDE]

I have a dashboard that displays data by week number. Since the turn of the year my rolling week table needs to reset at week 1.

For example I will trend 9 weeks of data today(weekNum()-9)
Then the next cell would be +1
Until I get 9 weeks minus the current week

Now I get week 52,53,54,55 etc and have to manually update it 50,51,52,1,2,3 etc

The problem will solve itself once we get to the 9th week this year, what can I use to reset the week?

My data is 9 rows worth the first cell today(weekNum)-9, then each cell after is +1

 

[sheetspread]

row() is a counter that changes as you copy down (use column() if going across). $I$1-91+(7*ROW(A1)-7)) takes the date entered in I1, goes back 7 * 13 days for n = 1 , 7 * 12 for n = 2, etc.