Percent change in tool tip

I figured out a solution.  Not the most elegant, but gets it done.   I removed the year from the column series and then created two measures to look at leads from the first year and last year like below.   This gets the tool tip to show the change between the two.   The only down side is that now more then two year's can't be viewed at once. 

First Year Leads = VAR minyear = Dim_Date[minyear] RETURN CALCULATE(Fact_Lead[Count Lead],Dim_Date[Year] = minyear)