Year % of total population 1960 22.1245574447917 1961 22.223023977287 1962 22.2802148454379 1963 22.2495824240488 1964 22.1199720707423 1965 21.9458122641982 1966 21.7882982682372 1967 21.6677365884095 1968 21.6000227554565 1969 21.5270700918339 1970 21.4325772337563 1971 21.3617342937607 1972 21.2732744456649 1973 21.1264283750534 1974 20.95190112152 1975 20.7741656715259 1976 20.588297427108 1977 20.4203681469023 1978 20.2976436950816 1979 20.2410236669585 1980 20.2694556358529 1981 20.3394175771652 1982 20.4229608642484 1983 20.5557894768945 1984 20.7070910765799 1985 20.8166798739334 1986 20.9041928474129 1987 21.0015864134843 1988 21.1047658764517 1989 21.1727757010873 1990 21.204503175626 1991 21.2037750413966 1992 21.1452735352485 1993 21.0181862553117 1994 20.8149231072325 1995 20.5142072419494 1996 20.0972857262643 1997 19.580079707741 1998 18.9577015656265 1999 18.2780888416575 2000 17.6255506985389 2001 16.9660733211981 2002 16.2933163209156 2003 15.708621469685 2004 15.2133276605596 2005 14.7738862009895 2006 14.430583239901 2007 14.2053065803085 2008 14.1192943491759 2009 14.129827215758 2010 14.1747169503369 2011 14.2653687528106 2012 14.4182318580313 2013 14.6241188410556 2014 14.8154511175566 2015 14.9839265906927 2016 15.18480589579 2017 15.3893943947464 2018 15.5239855953913 2019 15.6135838487328 2020 15.6502562923947 2021 15.626395804728 2022 15.5603352549995 2023 15.4348008413235