Thai Tax Brackets

I want to file for excess withheld tax from previous years

and need to know the Thai Tax brackets for those last few years.

Tax for this year's filing for 2009 is [after allowances and deductions]

20% for earnings that exceed 500K baht

Plus

10% for earnings greater than 150K up to 500K

I know that a few years ago it was something like

20% > 4 or 500K

10% > 100K up to 4 or 500K

So what are the these ranges for 2006, 2007 and 2008 ?

Anyone know ?

I can not find it at www.rd.co.th

Thanks