Is there a way to add/substract from a pivot variable?

I have this MDX:

SELECT
  NON EMPTY [DateOfSale].[Actual].[YearSold].&[$variable.Year] ON 0,
  NON EMPTY [Product].[P1].[Product Name].Members ON 1
FROM [HOLEFOODS]

And with pivot variable Year equal to, say, 2016 it works:

 

Now I want to add previous year  first with one pivot variable and one explicit reference. It also works:

0 3
0 70