Year % of total population 1960 39.592336873553 1961 39.62276939817 1962 39.5978315178197 1963 39.5216373740015 1964 39.4102648303476 1965 39.253929141134 1966 39.0554397436837 1967 38.839362111404 1968 38.6102852846683 1969 38.3571386925778 1970 38.0529966886043 1971 37.6904068380828 1972 37.2937427586781 1973 36.8699675450982 1974 36.4083316090159 1975 35.9170453997007 1976 35.4173722706574 1977 34.9115651926476 1978 34.4047722032869 1979 33.9015831145418 1980 33.4045535205692 1981 32.928707115454 1982 32.4736160352206 1983 32.0386200891695 1984 31.635302580114 1985 31.2664030616249 1986 30.9308872218807 1987 30.6255026436381 1988 30.3496589241894 1989 30.1078403641632 1990 29.8944499788201 1991 29.6924360889077 1992 29.4719124105365 1993 29.2270087422936 1994 28.9708250291295 1995 28.6961402519672 1996 28.3957235075886 1997 28.0628327261356 1998 27.6911811912214 1999 27.2756229149179 2000 26.8125653160442 2001 26.3160020480575 2002 25.7942727664892 2003 25.239386834502 2004 24.6478867743847 2005 24.0338902911975 2006 23.4221497474575 2007 22.8567197124241 2008 22.3523188527009 2009 21.8914432676801 2010 21.4798441699156 2011 21.1091599866842 2012 20.771601124245 2013 20.4724440702186 2014 20.2099150409439 2015 19.9743101950496 2016 19.7226070877104 2017 19.4177371496986 2018 19.1026198743247 2019 18.8264646121871 2020 18.6188701743694 2021 18.4569535059805 2022 18.3186998108983 2023 18.177371509033