I am evaluating your pivot table; I've updated one of your samples (http://docs.webix.com/samples/61_pivot/01_init/01_inline_data.html) and start playing with it.
I've added my source data, updated the configuration of the widget, run the sample locally, and I get the expected result.
It is basically a sales report where rows contain product brands and categories, and columns sum up sales (amount and quantity) by year (current and previous year). Nothing really new so far.
Next request was to display, for each row, the difference (as a perecentage) for amounts and quantity between the current year and the previous one.
Is it possible to get this result?