Year % of total population 1960 40.75389449559285 1961 40.5794654713902 1962 40.68561622826366 1963 41.24307369314819 1964 41.743148100167595 1965 41.96618988895501 1966 42.05127053954956 1967 41.919991374292536 1968 41.76345578216753 1969 41.68296628125468 1970 41.53743236372267 1971 41.401866741517246 1972 41.16297362484471 1973 40.91813991933161 1974 40.8529195307549 1975 40.8191512103452 1976 40.745444868269594 1977 40.29827114310555 1978 39.267805671523305 1979 38.18398358264682 1980 37.27371479583293 1981 36.449326190056084 1982 35.78639320240866 1983 35.04108718206278 1984 34.16903134401751 1985 33.36056754200011 1986 32.65708328887363 1987 32.11807299510394 1988 31.64826581182394 1989 31.259079589346303 1990 31.040648431484534 1991 30.833244835490063 1992 30.556554312379884 1993 30.26960351039422 1994 29.918018226037674 1995 29.491680551580004 1996 28.99741891934332 1997 28.404834358600915 1998 27.812625174592362 1999 27.25396313476475 2000 26.66438774720879 2001 26.011829928560243 2002 25.268663090994885 2003 24.53146597759334 2004 23.82450668784093 2005 23.096646547662356 2006 22.50263606592789 2007 22.110175367238607 2008 21.809161884800616 2009 21.572013929070508 2010 21.37720909733856 2011 21.217164998684613 2012 21.122705895308336 2013 21.068165960041448 2014 21.024758981204883 2015 20.956896955729018 2016 20.885500541119814 2017 20.857423141535925 2018 20.78190836353015 2019 20.628912863251877 2020 20.40297070455913 2021 20.098808298276584 2022 19.748357423362766 2023 19.36481879816593