caculate values for the previous year for the same period

[Anonymous]

I am comparing  values between this year and the last year for the same period

this year =num(Sum({1< DateTest={'>=$(=YearStart(Today()))<=$(=Today())'}>}[Prix de vente TTC] ),'# ##0 ;-# ##0 ')

But previous year doesnr' work it returns wrong values

num(Sum({1< DateTest={">=$(=MonthStart(today(),-24))<$(=MonthEnd(today(),-13))"}>} [Prix de vente TTC] ),'# ##0 ;-# ##0 ')

How to modify it ?

[Anonymous]

this might be helpful for you:

Current Month v. Same Month Last Year

Current Period and Last year Same Period

[maxgro · Accepted solution]

I suggest to add some flag in the calendar; if you want to stay with your expression maybe

num(

Sum({1< DateTest={'>=$(=( AddYears(YearStart(Today()),-1) )),<=$(=AddYears(Today(),-1))'}>} [Prix de vente TTC])

,'# ##0 ;-# ##0 '  )