I would like to add column before Total Column as Variance which should show difference between Last two months in this case June and July.

Note : -

1) Month and Category data are dynamic depding upon use filter selection.

2) Need to add vairence col for last 2 months.

For Example

 Catergory    April    May    june    July              Variance                 Total

------------------------------------------------------------------- --------------------

X                  10      20      30      40                10                         100

Y                  5        10      12      18                06                          45

Z                  1         2        2        4                 02                          09

if Need any more info pls let me know.

rgds,

Rajesh