Retrieve Quantity for Last Fiscal Week (using Dates Table)

Hi,

I am attempting to create a measure that will show the quantity for the last fiscal week to then us to create % var. I have working statment but it isn't taken into account where the fiscalweek of the year = 1 and then needs to refer to the max fiscal week of the previous year (52/53). Can anyone see where i am going wrong on the below. The issue is formula for retrieving VAR MXWeekLY. Thanks!

Week LW Quantity:=
VAR CurrentYear = SELECTEDVALUE(Dates[FiscalYear])
VAR CurrentWeek = SELECTEDVALUE(Dates[FiscalWeekOfYear])
VAR MXWeekLY =MAX(Dates[FiscalWeekOfYear],FILTER(ALL(Dates),Dates[FiscalYear]=CurrentYear-1))
RETURN CALCULATE([Quantity],FILTER(ALL(Dates),Dates[FiscalYear]=IF(CurrentWeek=1, CurrentYear-1,CurrentYear) && Dates[FiscalWeekOfYear]=IF(CurrentWeek=1,MXWeekLY,CurrentWeek-1)
))

Table containing Quantity

Date Dim Table (Joined on Date)