how to display variation in Matrix

Hello all,

I want to display YtoY variation in a Matrix but could not find the way to do it with duplicating columns

Example :

 For 2016 i want VAR N-1 and VAR -1 K appearing but not for 2015 since i d'ont have have any 2014 values in my database.

below the formula for VAR N-1

VAR N-1 = calculate (sum([VE]); filter ([Table]; [Table].[Year]="2016"))- sum([VE]); filter ([Table]; [Table].[Year]="2015")))

Could you please help?

Thanks