How to create Alerts by comparing two columns

Hi Experts,

Could you pls help me on this:

Requirement:

have 3 columns

Product, Year , sales revenue

i have created a cross tab with above objects.

Now i want to display the cell in Green color its its greater than previous value.

Sales revenue of a product for 2015: 5000 (it should display in Green)

Sales revenue of a product  for 2014: 2000(it should display in RED)

column 1 compare with previous column2 , coulmn 2 compare with column 3, column 3 with column 4

column1(2015), column2(2014), column3(2013)

Thanks in advance,