After studied the demo for pivot, I wonder if pqgrid can add formula for different feilds, if it's possible, would you like to provid a sample?. In your demo the formula is for two years in one field which is not what I need.
I made a demo with excel pivot table in attachment, the formula column is marked with yellow,the growthrate column is formula column,growthrate=(qty/lastYearQty-1).