Year % of total population 1960 28.046252044118237 1961 28.18781933812941 1962 28.35459139489045 1963 28.519689365934298 1964 28.68302304581548 1965 28.851954985614658 1966 28.72379742196836 1967 28.508729660744592 1968 28.346128776375508 1969 28.200173349196422 1970 27.99939213882932 1971 27.186998677849406 1972 26.093217479940282 1973 25.037769862606712 1974 24.057216056854532 1975 23.156086075074775 1976 22.56840481678415 1977 22.255517873036794 1978 21.946837222642788 1979 21.65649983261026 1980 21.39619798997741 1981 21.212178604537826 1982 21.080129977470833 1983 20.94790349484983 1984 20.812897048860645 1985 20.65996948192607 1986 20.510595184017916 1987 20.38570523562987 1988 20.277273723290854 1989 20.194466969333636 1990 20.13814985939339 1991 20.082269205234155 1992 20.03353076650868 1993 20.00578958445277 1994 20.017018236019503 1995 20.032032878222136 1996 20.057194711683703 1997 20.100904618380618 1998 20.12211411331244 1999 20.14752905925233 2000 20.172443112014047 2001 20.192252606608626 2002 20.284505139667903 2003 20.45290538632806 2004 20.625798058404044 2005 20.795980095331025 2006 20.956740806786932 2007 21.09874725301285 2008 21.21580647809523 2009 21.344029027203046 2010 21.492882704365048 2011 21.66669778256165 2012 21.867410452731363 2013 22.059056102549416 2014 22.231515156884722 2015 22.360707333865516 2016 22.474419562815008 2017 22.618881591956956 2018 22.797876842797855 2019 22.941024920447813 2020 23.090236930934644 2021 23.197369591545318 2022 23.21061175798153 2023 23.222064008587928