Trying to create a measure for previous month data

[Rahul__FCE]

Actually I am trying to create a measure for  pricing based on current month , previous month and same month last year. I have used the following syntaxes :

This_month = avg({<Month={$(=Month)}, Year={$(=Year)}>} Unit_Price_KG)

Previous_month = avg({<Month = {"=$(=Month - 1)"}, Year = {"=$(=Year)"}>} Unit_Price_KG)

same_month_last_year = avg({<Month={$(=Month)}, Year={$(=Year-1)}>} Unit_Price_KG)

The measure "this_month" and "same_month_last_year" is working. The measure for "Previous_month " is not working and is reflecting the data for the current month.

[anat]

Can you bypass Month field in Previous_month metric

[Rahul__FCE]

Sorry , I did not understand. Could you please elaborate