GDP growth rates in different regions of Thailand (2001 GDP set to =100).
Current market prices GDP growth is used, so the absolute numbers (not corrected for inflation)
are not that useful. Just compare the trends in different regions, with Bangkok showing the slowest growth.
The fundamental problem is the way GDP is generated throughout the country. Agriculture employs 41% of the labor force (2010) and generates only 12.2 % of GDP. This to a large extent, explains the low GDP in the northern and northeastern region of Thailand.
Needless to say, the income disparity that presently exists, will continue to exist for a long time and has negative social and political effects.
For a substantial overview of the Thai economy (latest report 2010) overall and in the provinces, check out this NESDB file. Hopefully the link stays active.