1960: 1.629 million
- 1961: 1.652 million
- 1962: 1.678 million
- 1963: 1.707 million
- 1964: 1.735 million
- 1965: 1.76 million
- 1966: 1.783 million
- 1967: 1.804 million
- 1968: 1.824 million
- 1969: 1.845 million
1990: 2.39 million
- 1991: 2.406 million
- 1992: 2.423 million
- 1993: 2.441 million
- 1994: 2.46 million
- 1995: 2.48 million
- 1996: 2.51 million
- 1997: 2.534 million
- 1998: 2.557 million
- 1999: 2.574 million
1970: 1.869 million
- 1971: 1.896 million
- 1972: 1.925 million
- 1973: 1.956 million
- 1974: 1.986 million
- 1975: 2.013 million
- 1976: 2.038 million
- 1977: 2.059 million
- 1978: 2.08 million
- 1979: 2.04 million
2000: 2.589 million
- 2001: 2.606 million
- 2002: 2.615 million
- 2003: 2.625 million
- 2004: 2.634 million
- 2005: 2.644 million
- 2006: 2.653 million
- 2007: 2.662 million
- 2008: 2.672 million
- 2009: 2.681 million
1980: 2.133 million
- 1981: 2.162 million
- 1982: 2.2 million
- 1983: 2.241 million
- 1984: 2.28 million
- 1985: 2.311 million
- 1986: 2.336 million
- 1987: 2.351 million
- 1988: 2.356 million
- 1989: 2.35 million
2010: 2.691 million
- 2011: 2.7 million
- 2012: 2.708 million
- 2013: 2.715 million
- 2014: 2.721 million
- 2015: 2.726 million
- 2016: 2.881 million
Source: The World Bank