Year % of total population 1960 24.323394272586306 1961 24.335964925085335 1962 24.30687123271017 1963 24.26584540756221 1964 24.220434909305695 1965 24.16729616639098 1966 24.11642863376236 1967 24.067775899839088 1968 24.02220085565501 1969 23.983130649190983 1970 23.933461925994752 1971 23.7801924768841 1972 23.64740951824518 1973 23.519224618069515 1974 23.404128306174865 1975 23.304656643945968 1976 23.225329773454227 1977 23.149387875030726 1978 23.07369402734702 1979 23.009505448894437 1980 22.95492983550624 1981 22.915524754915733 1982 22.879294027928257 1983 22.822899205075785 1984 22.74431432882489 1985 22.66368962441343 1986 22.581783605025475 1987 22.452117263627212 1988 22.332010023144715 1989 22.23764584282206 1990 22.206571262993208 1991 22.361091559843416 1992 22.786508529359683 1993 23.28265386554495 1994 23.820001589165866 1995 24.39987837971664 1996 25.035406812424533 1997 25.597901541365264 1998 26.163623328066986 1999 26.78007209841474 2000 27.45580494212901 2001 28.1703463205388 2002 28.678971465321055 2003 29.110090693406924 2004 29.54877671218497 2005 29.99255138207044 2006 30.4418457086065 2007 30.885850802664706 2008 31.303620715118747 2009 31.71063704150371 2010 32.12647365050533 2011 32.52853818860647 2012 32.91883928268518 2013 33.306763741271794 2014 33.63077288903759 2015 33.79313065112306 2016 34.33638814344845 2017 35.09689385337803 2018 35.5787528120819 2019 35.8708183776919 2020 36.176168172175714 2021 36.5446033325389 2022 36.9497069692507 2023 37.32325164681092