Table 1 Number of population in Thailand : 1911 - 1990 census years.
Census year Number of population
1911 8,266,408
1919 9,207,355
1929 11,506,207
1937 14,464,105
1947 17,442,689
1960 26,257,916
1970 34,397,374
1980 44,824,540
1990 54,548,530

Source :
(1) Report of the Survey of family Registration 1911, 1919, 1929, 1937 and 1947
(2) Population and Housing census 1960, 1970, 1980 and 1990, National Statistical office.