Prior YTD figure expression trouble

[#1]

Hi guys,

I'm trying to create an expresion in which we look at the previous years YTD figure?

My attempt was: [Code] sum({<Master_Calendar_Month_Key={">=$(=yearstart(Master_Calendar_Month_Key)) <=$(=Master_Calendar_Month_Key)"},
Master_Calendar_MonthYear = {"$(=date(AddMonths(Master_Calendar_MonthYear,-12), 'MMM-YYYY'))"}>}Count) but this didn't provide the correct details.

I also tried:

 sum({1<Master_Calendar_Month_Key={">=$(=yearstart(Master_Calendar_Month_Key)) <=$(=Master_Calendar_Month_Key)"},
 Master_Calendar_MonthYear = {"$(=date(AddMonths(Master_Calendar_MonthYear,-12), 'MMM-YYYY'))"}>}Count)

but this again did not give me the right result. Does anyone have any other suggestions, they would be most welcome.

Thanks,