Year % of total population 1960 25.034632121106057 1961 25.144339223965357 1962 25.135694696268846 1963 25.101910705137826 1964 25.088730143228407 1965 25.08946022326511 1966 25.09339966072402 1967 25.09233653571138 1968 25.072268184940036 1969 25.031011706678452 1970 24.944783554009753 1971 24.819504427118005 1972 24.658672521712433 1973 24.44937975972346 1974 24.19219001284108 1975 23.890128775378017 1976 23.55098375987152 1977 23.183821802774872 1978 22.78052156205599 1979 22.335133721835618 1980 21.889174999253843 1981 21.458930269405073 1982 21.04473035748082 1983 20.65207524807147 1984 20.26405371997445 1985 19.890920391438158 1986 19.53330222541403 1987 19.19691998910836 1988 18.90772337607985 1989 18.649575352860644 1990 18.412443380218235 1991 18.155746006664867 1992 17.911738347100762 1993 17.71335725072375 1994 17.499669126093032 1995 17.27047243409402 1996 17.046008936836966 1997 16.842577076176013 1998 16.66664761819908 1999 16.517034838255594 2000 16.381700040393778 2001 16.246273047162855 2002 16.111923229271426 2003 15.976863924453774 2004 15.837858510093454 2005 15.70788184100738 2006 15.597132786991253 2007 15.507709692205847 2008 15.453452095446515 2009 15.433524690262558 2010 15.41997077351035 2011 15.402206070375499 2012 15.36250428112318 2013 15.312941302303459 2014 15.253996791137434 2015 15.188082591800704 2016 15.128188562934461 2017 15.081407188163135 2018 15.02314878471166 2019 14.946084234304031 2020 14.855249167294772 2021 14.755297500224383 2022 14.632946766848304 2023 14.488740384233033