Rolling Quantity

[WalidChoukri]

Hello Everyone,

I'm trying to get the Rolling quantity of a product, I'm using this code in the script :

Demande:
LOAD *,
If(Article = Previous(Article),Rangesum(Quantité_ND,Peek('Rolling')),Quantité_ND)as Rolling
Resident ND
Order By Article, YearWeek;
drop Table ND;

Article, YearWeek and Quantité_ND are fields in the table ND, however the result i'm getting is confusing, as you can see in the screenshot below, can you help me guys, what i'm doing wrong.

Many thanks.