Provinces where no TAO became a municipality yet

As I suspect that the upgrade of TAO to municipalities has ceased for the moment, it's now possible to notice some funny statistics about the upgrades. While adding the municipal constituencies from 2003 - at that time it were almost only the original municipalities and the former sanitary district which had the constituency boundary announcement in the Royal Gazette - I noticed that in Krabi province there are only these kinds of municipalities, all the TAO created in the 1990s are still at that level. Actually, there are five provinces which haven't had any TAO upgrade so far.

• Krabi - 51 TAO
• Nakhon Nayok - 40 TAO
• Narathiwat - 74 TAO
• Pattani - 101 TAO
• Prachuap Khiri Khan - 45 TAO

Only one of the original created TAO in these provinces does not exist anymore - Chehe in Narathiwat was merged into the subdistrict municipality Chehe in 2004. Interestingly, three of these provinces are in the South, and not one is in the poorest area of Thailand, the Northeast.