Year % of total population 1960 18.27826638494531 1961 18.48751567549595 1962 18.733616090089576 1963 18.985164625708002 1964 19.24291709915266 1965 19.50440454443043 1966 19.767949869706566 1967 20.044068963073894 1968 20.327491787776523 1969 20.61537722019043 1970 20.908627549244468 1971 21.244042001696897 1972 21.63322520518936 1973 22.01824398141132 1974 22.414026713836755 1975 22.67114787415948 1976 23.09871625481412 1977 23.52275000360405 1978 23.92553135248885 1979 24.319309576948868 1980 24.74271436494987 1981 25.14966584731713 1982 25.458135091755707 1983 25.772923728264097 1984 26.09646999241141 1985 26.427441257323427 1986 26.764287988420165 1987 27.101960488389647 1988 27.44022388340581 1989 27.780908158489115 1990 28.175546228480705 1991 28.466145603943037 1992 28.736858735743674 1993 29.001205978486567 1994 29.267772043362378 1995 29.527788963119768 1996 29.79328269483901 1997 30.0640024240263 1998 30.33413755262209 1999 30.60230038602714 2000 30.878811363508447 2001 31.2067138449723 2002 31.581762292600416 2003 31.96287537834179 2004 32.34837147387805 2005 32.7430794756753 2006 33.14652684144704 2007 33.55494302932066 2008 33.96367860581518 2009 34.376801830703705 2010 34.796915942679504 2011 35.226314071019424 2012 35.657371729302824 2013 36.10951515454771 2014 36.580745347691916 2015 37.045785545536866 2016 37.504643796321325 2017 37.96771980640371 2018 38.441035409288496 2019 38.92469992613001 2020 39.41817893758412 2021 39.92190390743256 2022 40.43746870644483 2023 40.9606602965532