Year % of total population 1960 15.333922800552774 1961 15.734759267603854 1962 16.141711697165015 1963 16.550167431285157 1964 16.960227025986963 1965 17.37373609611471 1966 17.806293235480556 1967 18.22364388847182 1968 18.63929194172404 1969 19.059275201551458 1970 19.48064839336647 1971 19.916473096892968 1972 20.371678345343224 1973 20.83024416386627 1974 21.290184387569745 1975 21.74824000845361 1976 22.223792635337073 1977 22.573531395655934 1978 22.83963556805183 1979 23.08659588426968 1980 23.31407371378645 1981 23.211391292143137 1982 23.143941310159075 1983 23.4071574384529 1984 23.684585754285237 1985 23.992780458577553 1986 24.352679827752965 1987 24.285694782642935 1988 24.134851585055443 1989 24.025883918973896 1990 23.677411268587672 1991 23.35311914460761 1992 23.20902493861755 1993 23.40358357391119 1994 23.66265194088016 1995 23.69838516969434 1996 23.74219496493885 1997 23.82877559639256 1998 23.907994433342424 1999 23.98219488886695 2000 24.043596535190513 2001 24.089403664359143 2002 24.31545672748768 2003 24.55598103671977 2004 24.630641012263908 2005 24.70682260618637 2006 24.801051577703277 2007 24.890783827934012 2008 24.98971540484097 2009 25.092733127173755 2010 25.187785605499414 2011 25.31738252628392 2012 25.368306850313104 2013 25.336395113631937 2014 25.194596981413795 2015 24.963290205073207 2016 24.84100859154221 2017 24.82006998017492 2018 24.830003919055766 2019 24.895411153908633 2020 25.03165046272724 2021 25.200485804512272 2022 25.362812458463 2023 25.51128754365108