Year % of total population 1960 5.7469962764182645 1961 6.278338896870837 1962 6.600849171071002 1963 6.9345429859094585 1964 7.262846853189458 1965 7.5592343643910445 1966 7.813879512849689 1967 8.033716132117696 1968 8.24455000944199 1969 8.472444524509948 1970 8.72173854080058 1971 8.96220069503897 1972 9.243816460605894 1973 9.552935724446225 1974 9.88260788830915 1975 10.229854967480346 1976 10.59369078765336 1977 10.970544653629972 1978 11.360139600504938 1979 11.748381162086599 1980 12.119473875219775 1981 12.462946855032614 1982 12.806684521074848 1983 13.168981988623552 1984 13.547708650708302 1985 13.955518763929234 1986 14.396706373550968 1987 14.85387428288368 1988 15.328103530390703 1989 15.64435866498993 1990 15.973489833581317 1991 16.315160962504528 1992 16.671906685931752 1993 17.64894105323863 1994 18.493397370676725 1995 18.596324954446317 1996 18.823864685597886 1997 19.159878498873177 1998 19.568250471575706 1999 19.985780435711938 2000 20.428631189678185 2001 20.905713151836213 2002 21.415864091103764 2003 21.93949051106982 2004 22.47313582325077 2005 23.023333053785134 2006 22.879146919431278 2007 22.713213660371157 2008 22.561720548167113 2009 22.423430412538696 2010 22.313441182131985 2011 22.207613586791595 2012 22.114475499286453 2013 22.029897995125122 2014 21.952605948397608 2015 21.88138487392799 2016 21.814407740459455 2017 21.75156743554365 2018 21.69521115481306 2019 21.658251137255018 2020 21.650703931736505 2021 21.682256525837584 2022 21.760453146841137 2023 21.887110593022886