Year % of total population 1960 40.2241486385259 1961 39.8636812166546 1962 39.4946247237878 1963 39.2078669644912 1964 38.9332767021413 1965 38.8789048567718 1966 39.0997041827054 1967 39.3020594965675 1968 39.4831370517265 1969 39.6379735485317 1970 39.7620306811475 1971 39.8507499738453 1972 39.898678429446 1973 39.9071631775808 1974 39.8848341948397 1975 39.9937679753918 1976 40.2169767760381 1977 40.3466775390254 1978 40.3148305402034 1979 40.1204635103042 1980 39.8782979147463 1981 39.6890722456124 1982 39.5427804711256 1983 39.4348985223698 1984 39.4105810034064 1985 39.5110605489738 1986 39.7607923940998 1987 40.1958567993195 1988 40.8300239383415 1989 41.5221271956357 1990 42.0713594141189 1991 42.3676528543445 1992 42.5398587478707 1993 42.7395952737715 1994 42.9359155361476 1995 43.0872207957394 1996 43.1705621164749 1997 43.1959314203863 1998 43.1761629956179 1999 43.1247829282674 2000 43.0845798332004 2001 43.0941846649668 2002 43.1399396573474 2003 43.1884336340529 2004 43.1765291015694 2005 43.0396873663681 2006 42.8112002791171 2007 42.5335160620074 2008 42.1823806786942 2009 41.7637535897291 2010 41.392796327745 2011 41.1014253676629 2012 40.7572282254474 2013 40.2655922448786 2014 39.6457719672864 2015 39.0482189195174 2016 38.4890270970355 2017 37.8919914577694 2018 37.2656161154436 2019 36.6113535412701 2020 35.945061327159 2021 35.2940931547335 2022 34.7119875105868 2023 34.214675039468