Year % of total population 1960 25.287150127226464 1961 25.942004948906582 1962 26.52700338975857 1963 27.09765904181623 1964 27.745876574841837 1965 28.522127987663843 1966 29.428627483099966 1967 30.48659812206644 1968 31.63729346852668 1969 32.759085744090314 1970 33.675570272259016 1971 34.17900289263229 1972 34.566365285937806 1973 34.88998487556908 1974 35.24643120689661 1975 35.690748162992655 1976 36.211855102117255 1977 36.80696346995004 1978 37.4704458109024 1979 38.17722234988422 1980 39.22429819089208 1981 41.29697842933591 1982 43.51043325411531 1983 45.86453358331788 1984 48.36432738570476 1985 51.000207284572106 1986 53.79348735934377 1987 56.74921916992315 1988 59.88206907629413 1989 63.18762568995764 1990 65.78314956177552 1991 65.8264904789577 1992 65.91138064072726 1993 65.86527384755125 1994 65.76287043017486 1995 65.66397953030366 1996 65.43615448947621 1997 65.33344150576018 1998 65.46323412149 1999 65.64189026497067 2000 65.82298611375359 2001 65.60304432783924 2002 65.43945250949277 2003 65.31960131674724 2004 65.22734720051176 2005 65.24278516403314 2006 65.44060334057427 2007 65.74555345698315 2008 66.05249961046205 2009 66.33371742669921 2010 66.58987914900477 2011 67.28321062800987 2012 68.02008976229939 2013 68.72101544163958 2014 69.76822936263075 2015 70.92077350433257 2016 72.21919222044271 2017 73.89746325579213 2018 76.85765499221195 2019 76.75672747608256 2020 74.6114420685059 2021 74.9522556979771 2022 75.85174805977306 2023 76.10103406722607