Year % of total population 1960 21.2150769554844 1961 21.2982535722386 1962 21.3051702679265 1963 21.2512232007828 1964 21.1668647387649 1965 21.1082276717291 1966 21.1129387853526 1967 21.1747423997275 1968 21.2708601851618 1969 21.3703303623935 1970 21.4835291978645 1971 21.5873184787413 1972 21.5541458075762 1973 21.3221440651752 1974 20.9365985050125 1975 20.421306643986 1976 19.9598591133587 1977 19.6221306650971 1978 19.2351978193268 1979 18.773489348888 1980 18.293302287786 1981 17.858143335149 1982 17.481136297005 1983 17.1349655986522 1984 16.8000968566975 1985 16.465091533095 1986 16.2285760912702 1987 16.1198115423002 1988 16.0439297211566 1989 16.0183871720745 1990 16.0481929424651 1991 16.2069562330236 1992 16.4891575682251 1993 16.738174803133 1994 16.925501261709 1995 17.0255226764965 1996 17.1233427922616 1997 17.2366830722717 1998 17.2802352109062 1999 17.2482252851974 2000 17.1372237305282 2001 17.0664320341815 2002 17.0439604121862 2003 16.9655827937563 2004 16.8288328050395 2005 16.6382558170385 2006 16.4168596694389 2007 16.2049802740423 2008 16.0041559988477 2009 15.8019791807142 2010 15.6271008236025 2011 15.5260139780381 2012 15.473045813606 2013 15.4060853348686 2014 15.3297599627127 2015 15.2484740119613 2016 15.1266021872509 2017 15.074599763944 2018 15.141876621746 2019 15.2485095330854 2020 15.3054277156841 2021 15.2594196897793 2022 15.1507927389706 2023 15.0268183282814