Set analysis for rolling 12 month where year <2024 vs =2024

[Ethel]

Hello Community, could you please help me.

I have a set analysis formula that I use when I'm calculating trend. Another dimension is PeriodYear. 

avg(aggr(sum({< PeriodType={'Rolling 12 Months'}, PeriodYear= {"<=2024"}>} [# HeadCount]),[%PeriodSKey]))

I use this formula when I'm calculating  the same number in the table 

avg(aggr(sum({< PeriodType={'Rolling 12 Months'}, PeriodYear= {"2024"}>} [# HeadCount]),[%PeriodSKey]))

Could you please help me understand why I'm getting  similar but different results for 2024? And how can I make them the same. 

Thank you very much in advance! 

[Ethel · Accepted solution]

I found a problem.

It should look like this

avg({< PeriodYear= {"<=2024"}>}aggr(Sum({< PeriodYear= {"<=2024"},PeriodType={'Rolling 12 Months'}
>} [# HeadCount]),%PeriodSKey))