I am displaying numerical values in a cross tab.  eg.

 

1/2/12   2/2/12  3/2/12 and so on

26             52        54

11               12      8

 

And I want the colour to change to red if the value goes up by more than 10%, green if it goes down more than 10% and stay black if it is within 10% of the previous number.

 

So in the example above 26 would be black 52 would be red and 54 would be black.

 

Line 2 - 11 would be black, 12 would be black and 8 would be green.

 

I can find where to write a formula for the font colour - Right click on field, format field, font, and then the formula button next to Colour, but I don't know how to write the formula.

 

Any help gratefully received.  Many thanks.