count a value on several week

Hi community,

I have a table with dates ("Date de RDV")  and some codes "Motif Echec".

For the code R3 (or any other code), i try to count how many "num inter" we have for the last 5 week, each week of the year.

To be more precise in my request, here my data and the result I try to have

DATA:

RESULT:

this result show for example in week 20 (S20) the sum of R3 codes of weeks 20, 19, 18, 17 and 16.

in week 21 (S21), the sum of R3 codes of weeks 21, 20, 19, 18, 17

etc...

thanks for your help

Best regards