The spreadsheet is a ODS file, the file format used by OpenOffice. Microsoft started to support it with Office 2007 Service Pack 2, for older versions one have to install a plugin. But due to the common demand I have added the Excel (XLS) version as well, but that will get updated much less regularly.
I started with this spreadsheet many years ago to collect the various data on the Thai provinces while slowly creating all the articles on Wikipedia. It has since grown a lot, from just two sheets with the provinces and the provinces sorted by population, area and population density, to now 24 sheets. I am only listing the most important ones here, so if you are looking for any of the following information on all the entities you have now found what you were looking for.
- Districts (Amphoe, อำเภอ) - Population in census 1990 and 2000, area, date of creation, geocode in TIS1099, Census 1990 and 2000, (main) Postal code
- Subdistricts (Tambon, ตำบล) - date of creation and upgrade (from Royal Gazette), geocode in TIS1099, subdistricts from which it was split off
- Municipalities (Thesaban, เทศบาล) - dates of creation or upgrade for all five municipal levels (TAO, Sukhaphiban, Thesaban Tambon, Thesaban Mueang, Thesaban Nakhon), geocodes both by DOLA and TIS1099
- TAO (องค์การบริหารส่วนตำบล) - date of creation, DOLA code, corresponding Tambon; list includes all the former TAO either abolished or upgraded to municipalities as well