Year % of total population 1960 16.185419316855107 1961 16.355441375459435 1962 16.49301511937779 1963 16.607754667361935 1964 16.72612429068586 1965 16.841227640929983 1966 16.963118322144936 1967 17.104209259329522 1968 17.252779621231074 1969 17.395874518622506 1970 17.566907504286483 1971 17.703654885441424 1972 17.74354708068149 1973 17.773535909185338 1974 17.81890499572796 1975 17.868889393964718 1976 17.921199075271677 1977 17.98067709082302 1978 18.038699583050587 1979 18.09634048020331 1980 18.15160122096948 1981 18.19285523880126 1982 18.190659105350566 1983 18.19925636309272 1984 18.21489324632912 1985 18.23824868670185 1986 18.272232115475354 1987 18.37188669075554 1988 18.36419446071907 1989 18.40039070673319 1990 18.40968634773915 1991 18.390383465477548 1992 18.38420937196504 1993 18.38302230112228 1994 18.392298072155608 1995 18.40192033825751 1996 18.410974779487468 1997 18.41814167086348 1998 18.426312738568726 1999 18.440743080092897 2000 18.462892719981937 2001 18.47772047609522 2002 18.491457754845918 2003 18.50169585876649 2004 18.509419872087815 2005 18.52815216988177 2006 18.56519606412528 2007 18.594644531228823 2008 18.62970380470359 2009 18.69493206939542 2010 18.77527897490856 2011 18.940870331216942 2012 19.023673749726083 2013 19.08373895531861 2014 19.144168081997424 2015 19.21469160899219 2016 19.2886269080741 2017 19.379081294987767 2018 19.467064236466378 2019 19.549361393672765 2020 19.62557037701407 2021 19.714422351375006 2022 19.72689725174271 2023 19.70073484160941