As the title says - what's the average salary increase this year for skilled & un skilled workers?

There is no automatic annual salary increase in Thailand. You can find some information on Google.

Bit of Info :Not exactly what you are looking for but for a rough guess...

Been a couple of increases eg UK has gone up to £5-93 Hour...WOW

National Minimum Wages...from wiki...

Thailand ranges from 148 Thai baht to 203 baht per day, depending on the cost of living in various provinces; set by provincial tripartite wage committees that sometimes include only employer representatives

to compare you average joe in the West...

United Kingdom £5.80 per hour (aged 22 and older),

£4.83 per hour (aged 18–21) or £3.57 per hour (under 18 and finished compulsory education )

United States the federal minimum wage is US$7.25 per hour; states may also set a minimum, in which case the higher of the two is controlling.

Australia 543.78 Australian dollars per week; set federally by the Australian Fair Pay Commission[4]

and how much does it come to a ltr of Petrol..

http://en.wikipedia.org/wiki/List_of_minim...ages_by_country

I never automatically raise a salary and I would certainly never do it annually as that would set in motion expectations and you could find yourself short of staff. Link it all to length of service and appraisals, even if just by yourself. Almost certainly you get more for your money from experienced staff who have been with you some time and they are the ones to be rewarded.

If your business pays low salaries but has a high turnover of staff, you could raise salaries every 3 months or 6 months by a small amount rather than front loading a salary increase from day one. That has worked well for me in the past.

None this year in Prachinburi.

Last year base daily wage 163B

This year same. 163B