Rolling 12 Month Average in Magic ETL

Hi there!

Was hoping someone would have a solution for what I am trying to do. I want a 12 month historical average in line with the current month in my dataset. (Sample datasets will only show 3 month)

This is a sample dataset of what I am working with:

*"Desired Column" would be the field that holds the historical average.

In this case the Desired Column in the first row = 33.3 because:

1. Add all the "Type" = Cloth and "Name" = Chest has a weight of (33.9 + 33.3 + 32.6)

2. Divided by the last 3 months (99.8 / 3) = 33.3

I am looking to get this done within Magic ETL using whatever tiles makes the most sense.

Any help would be appreciated!

Thank you in advance!