Year % of total population 1960 26.8890653958168 1961 27.3799618227204 1962 27.9066600081718 1963 28.4006925968157 1964 28.7943262411348 1965 29.021198156682 1966 29.3688986663 1967 29.9564927434977 1968 30.3814514476419 1969 30.4352539433032 1970 30.1880617305707 1971 29.7774546818939 1972 29.2506131744919 1973 28.6264783651383 1974 27.9646187866551 1975 27.2888438647588 1976 26.6356017546555 1977 26.0040712139326 1978 25.3549664604663 1979 24.6338820221428 1980 23.7328353598607 1981 22.6508955728287 1982 22.0153893984144 1983 21.7624653739612 1984 21.2811607259279 1985 20.5434894258095 1986 19.9190869322106 1987 19.4846226514118 1988 18.9680693592726 1989 18.3990627148349 1990 17.7881070385201 1991 17.2401663224165 1992 16.7980308465789 1993 16.4100006761782 1994 16.0779527172043 1995 15.7935719677407 1996 15.5992049573249 1997 15.4965832843759 1998 15.4267436776584 1999 15.3613586170132 2000 15.2774310677408 2001 15.244028310233 2002 15.264966795345 2003 15.2494672394547 2004 15.1767435512488 2005 15.0052301582828 2006 15.0933988195037 2007 15.4614710529177 2008 15.786601801328 2009 16.0923197746845 2010 16.3186263886073 2011 16.435327877564 2012 16.4126034148917 2013 16.2513223991649 2014 15.9400459359271 2015 15.5034113637789 2016 15.1729034125764 2017 14.6953065218422 2018 14.095462816693 2019 13.6718494164494 2020 13.3346203346203 2021 13.0747526381051 2022 12.7950240529164 2023 12.4200879033064