The administrative villages (Muban, หมู่บ้าน) are the central administrative subdivision for which it is most difficult to find authoritative information. I still haven't find any complete official lists online by the Department of Provincial Administration, though it seems they publish a list every year named "ทำเนียบท้องที่ พุทธศักราช ####", but only the 2003 edition is online and hardly readable as being scanned at too low resolution. Haven't had any luck yet to find any of these book in a library in Bangkok...
While it is difficult to get a complete list of all the Muban, at least the total number should be easier to find. Every year DOPA publishes a short statistics showing the numbers of the administrative subdivision, thus the latest official number is 74965. I already mentioned that my own list compiled mostly from the postcode page of noplink has a few more, 75090 as of December 31st 2015. Another source is the Statistical Yearbook published by the NSO, the 2015 edition lists however a much lower number of 55387. Apparently NSO only counts those Muban which are still in use administratively, the difference of almost 20000 Muban are probably those which no longer have a village headman as being part of a municipality.
Since I collected the DOPA number for several years already, and also now worked through all the yearbooks available online, its possible to compile a little chart showing the development of the numbers. And as since 2002 the creation of new Muban was announced in the Royal Gazette, I could also calculate the past numbers from my data. The actual numbers can be found in this spreadsheet, but the graphics is what shows most.
My numbers (yellow) and the DOPA numbers are almost same, the difference of 125 is hardly visible in this scale. However for 2002 the difference is already 1241. thus apparently not all Muban creation were announced in the Royal Gazette. The Yearbook numbers are steadily decreasing, interestingly in the 2010 yearbook the DOPA full number from 2008 was published.
I'd love to get my list in better sync with the other data, but for that I would need access to those Local Directory (ทำเนียบท้องที่) books. Also, there are holes in the Yearbook graph, some of the latest issues are not found online. During my latest stay in Bangkok I tried to find some in a library, but despite having them in the catalog they weren't on the shelve where the belonged. The online library of the NSO is sadly also no help, there are only few issues listed there, and most of those don't work. If anyone this access to a university library having these books is willing to help, please contact me.