Year % of total population 1960 7.97346091807391 1961 8.18174350581033 1962 8.3621920218096 1963 8.54891797504127 1964 8.78476336527883 1965 9.06347686365954 1966 9.33632086781814 1967 9.58471827718202 1968 9.81636487762956 1969 10.0320469652934 1970 10.2598105320411 1971 10.5208768635694 1972 10.8001465680654 1973 11.0710236494521 1974 11.2727894822073 1975 11.3761700496677 1976 11.424420233882 1977 11.4467153433631 1978 11.4330616562583 1979 11.3776970849922 1980 11.2577054565964 1981 11.0756970877243 1982 10.8672737242498 1983 10.6524591434519 1984 10.4849366203812 1985 10.4006082465876 1986 10.4047500991134 1987 10.4864557371246 1988 10.6254864478913 1989 10.7943152997849 1990 10.9811225863063 1991 11.1803039231955 1992 11.4181511043363 1993 11.6939496941754 1994 11.9580480506803 1995 12.2374636985483 1996 12.548273492204 1997 12.888172344793 1998 13.2565163842799 1999 13.623338719584 2000 14.0243188444166 2001 14.4741417617612 2002 14.9315134340729 2003 15.3888908903572 2004 15.8387607517229 2005 16.260490115259 2006 16.6732597406838 2007 17.0749300784512 2008 17.4283098055361 2009 17.7102725721503 2010 17.9807318752661 2011 18.2446756602649 2012 18.4678101458506 2013 18.7074818138033 2014 18.9943162230137 2015 19.2703401366742 2016 19.5037382312653 2017 19.7321868167811 2018 19.943656878911 2019 20.177492196612 2020 20.4200383190737 2021 20.5900058152251 2022 20.7961658948639 2023 21.2197907445008