Dynamic Previous Year Calculation in crosstab

[Cognos Talk]

I need to create dynamic previous year calculation for % change in the same query where current total is
And i am not sure how to do it. Can someone help please?
I am using
Case
when  ([IRIS].[MCI Go Data].[Occurrence Date] between _add_years(cast(#prompt('pDateTo')#,Date),-1) and #prompt('pDateTo')# )then 1 else 0
end
Probably it is not correct since it gives me the total for current year only, and it is not dynamic
Thank you very much