Year % of total population 1960 7.71635019639641 1961 7.85145734074357 1962 8.01061457817744 1963 8.18511767428129 1964 8.39296444065684 1965 8.66433496480584 1966 8.97044204987282 1967 9.24580249673495 1968 9.47366456337805 1969 9.68097990529851 1970 9.8872299302843 1971 10.0911685749632 1972 10.2826198311079 1973 10.4685328963381 1974 10.6674529081078 1975 10.8597505454599 1976 11.0108164932092 1977 11.1433449220129 1978 11.2578944225822 1979 11.3308930218713 1980 11.2519684397546 1981 10.9898166772294 1982 10.6559745139412 1983 10.3133927840913 1984 10.0989594070558 1985 10.0575769339899 1986 10.1158684391825 1987 10.2291894970493 1988 10.3811844325811 1989 10.5650496419517 1990 10.7686261596033 1991 10.9933297232507 1992 11.241023632328 1993 11.5124157465703 1994 11.8060517743613 1995 12.1554050864193 1996 12.5369568433487 1997 12.8961648946542 1998 13.2365729356896 1999 13.5712023747131 2000 13.8995907453313 2001 14.2326027862982 2002 14.5311924233037 2003 14.7588621057031 2004 14.9854398823271 2005 15.2333786500603 2006 15.4867264328348 2007 15.7561996195191 2008 16.0257232798091 2009 16.2194743979452 2010 16.25613824028 2011 16.364642526361 2012 16.6721111999204 2013 17.0364236772842 2014 17.4491798949066 2015 17.894867607751 2016 18.3266188840298 2017 18.761151395926 2018 19.2242217667874 2019 19.6906954725528 2020 20.1009991778588 2021 20.5009461361761 2022 20.9591366157132 2023 21.419349999257