Year % of total population 1960 43.1310430706124 1961 42.9494185733995 1962 42.8527323247916 1963 42.6611570247934 1964 42.3591594688668 1965 41.9366637462467 1966 41.4062961182652 1967 40.725620154062 1968 39.9492185201066 1969 39.1934940165178 1970 38.4280916650453 1971 37.6186954341044 1972 36.690708599876 1973 35.6158037917646 1974 34.4725334221815 1975 33.3498035921634 1976 32.1853168280427 1977 31.0564462991434 1978 30.1394602999773 1979 29.423765442054 1980 28.9240602892406 1981 28.6966868167408 1982 28.4832689017048 1983 28.1802050782783 1984 27.9012691957086 1985 27.534973169143 1986 27.0591606896659 1987 26.5275407292475 1988 26.0813131980445 1989 26.0056815103219 1990 26.5592780563524 1991 27.6965696098078 1992 28.102405561927 1993 27.5241846323936 1994 26.8469626090041 1995 26.0090850097339 1996 25.1488975911958 1997 24.4795866011874 1998 23.9784245154407 1999 23.608504955852 2000 23.2556312499299 2001 22.8794636703955 2002 22.5041130517209 2003 22.1027820627609 2004 21.6689206164241 2005 21.3578103997545 2006 21.2401876441455 2007 21.1831134346555 2008 21.1304543042573 2009 21.0513849131153 2010 20.7486433828476 2011 20.2250019745676 2012 19.7372480083046 2013 19.3487558320373 2014 19.0455045659015 2015 18.7996067429202 2016 18.5717214384812 2017 18.3348587091053 2018 18.0697706242362 2019 17.7673391737323 2020 17.3510219591029 2021 16.7994067760814 2022 16.240781624313 2023 15.7117720673335