05 to 06>>annual increment = 9.03%
06 to 07>>annual increment = 11.46%
07 to 08>>annual increment + promotion = 14.29%
08 to 09>>annual increment = 8.00%

Base on my calculation, your stat board give you a very good annual increment throughout all years, with the 'worst' annual increment is 8%!!!

I dun think if u join private sector in 2005 u can get this kind of annual increment, assume that u still get the same starting pay of $1440.

Most of the time normally, private sector only give u annual 3% increment, and if u leave the private sector in 2009, I can estimate that your 2009 pay with 1 promotion is at most around $1700+/-$50 only.

I think you should continue to stay in the stat board.
I only do my calculation base on basic salary, i dun noe how much bonus u are getting in the stat board.