Current Month, Previous month and YTD

[suvechha_b]

Hi All ,

I have got current month field as UW_MONTH_KEY = 201909 which is March 2019 . 

I have got measure

1.Avg Claims Current month 

2.Avg Claims Previous month

3. Claims YTD.

My expression -

1.Avg Claims Current month  -

Avg({$<[UWY_MONTH_KEY] = {"Max(UW_MONTH_KEY)"}>} GROSS_CLAIMS_PAID) + Avg({$<[UWY_MONTH_KEY] = {"Max(UW_MONTH_KEY)"}>} GROSS_CLAIM_OUTSTANDING)

How to calculate the above three measure using set analysis. ?

Please kindly assist .

Thanks in Advance.