Year % of total population 1960 16.698834779280375 1961 16.831982920402563 1962 17.01885310461076 1963 17.207628226986845 1964 17.398917323536445 1965 17.59087343390042 1966 17.785364733698554 1967 17.982277001132832 1968 18.181923642993954 1969 18.385424330103593 1970 18.595867250245885 1971 18.846156769423267 1972 19.175246174502657 1973 19.500692264557436 1974 19.84726970541011 1975 20.228190438169047 1976 20.620740139076215 1977 21.02269846855971 1978 21.434400826025577 1979 21.85960337483033 1980 22.304321358026886 1981 22.69994153118157 1982 22.963249142746967 1983 23.220235485086523 1984 23.476012474647547 1985 23.73544790152496 1986 24.00187727224579 1987 24.271533061546283 1988 24.543485800453674 1989 24.8106298906593 1990 25.07906467423147 1991 25.336239523302268 1992 25.55933621094728 1993 25.781157569343392 1994 26.00895584096549 1995 26.240197451945075 1996 26.476766669176968 1997 26.714403450997466 1998 26.951286029553106 1999 27.185145023141864 2000 27.424189877316735 2001 27.702820863047528 2002 28.039666133254507 2003 28.37639161293703 2004 28.72107854888914 2005 29.068671235820783 2006 29.418567427558752 2007 29.774648357501544 2008 30.133976109623635 2009 30.493168568931928 2010 30.85539270064633 2011 31.219043068444993 2012 31.590545925138105 2013 31.97027604561879 2014 32.35853413732981 2015 32.755806006545555 2016 33.16234063548332 2017 33.57861344235522 2018 34.00589919797481 2019 34.44463405787614 2020 34.89320578861991 2021 35.3519249926791 2022 35.82499864951431 2023 36.312297777191326