Dynamic aggregated average

[Luca_perdic]

Hi,

I have a data set with all the costs by data that are categorized and recapped in a table as follow. Now i would like to create a column sensitive to the selected YearMonth that gives me back the average monthly costs per category in order to see each month for every category how much i have spent compared to the dinamic average.  Mind that behind every line of the table there is more records but the average i need is based on the total monthly costs per category.

Thank you 

Br Luca

[BrunPierre]

=Avg(Aggr(Your Expression), YearMonth, Category))

[Luca_perdic]

Hi BrunPierre, 

I had tried already but i get the same value i have on each month and not the avg value of all the selected month