Insert new columns and calculate the percentage for Year over Year

Hi,
I have the followings in a table:
FAC_NAME 2006 2007 2008
MAL 300 200 600
GES 200 500 400

Pls. note the Years are dynamic, meaning it can start from 2005 or 2006 and can go up to 2011 or 2013 etc.
So, what I want to do here is to insert a new column and calculate the percentage for year over year to see if the revenue has increased or decreased. In this example, I would like to see the following results:
FAC_NAME 2006 2007 2008 2007 - 2006 % 2008 - 2007 %
MAL 300 200 600 -33% 200%
GES 200 500 400 150% -20%

Here is the formula I used to calculate the percentage for (2007  2006 %) is (2007  2006)/2006. See attached sample file. Pls. feel free to change the structure; i just want the best way to achieve the final result. Thanks

Ka-ching, the bill just went up. This what you're after?

David,
The years are dynamic meaning the MainTable may contain the years like 2009, 2010, 2011 etc. And i want always to calculate the year over year percentage like in this case (20010-2009)/2009 and so on. So this is my main problem; the years are not fixed years they can change and they always be incremental years. I know you are spending some time on this but once i get what i want then i will make you happy. thanks.

I suspect this is beyond my skills. I think it needs some VBA code to cope with this which I am decidedly inept at