Year % of total population 1960 38.0675281699719 1961 38.8942384691281 1962 39.6678323434408 1963 40.5649289540031 1964 41.6150294787127 1965 42.6330327205712 1966 43.5595747272562 1967 44.3452120143849 1968 44.921775788551 1969 45.2541313128672 1970 45.4445332814995 1971 45.5938893537413 1972 45.6867415461762 1973 45.7072035147758 1974 45.6505839215511 1975 45.4976352762333 1976 45.2502461440162 1977 44.9151232801447 1978 44.5039446291405 1979 44.05649528673 1980 43.6431693152234 1981 43.2987814659552 1982 43.0023173234661 1983 42.7424282050475 1984 42.5146875594395 1985 42.3275036482738 1986 42.1872398360942 1987 42.0632139031309 1988 41.912197634165 1989 41.6782953987942 1990 41.3587652265881 1991 40.9958017368941 1992 40.5829929753876 1993 40.1045407205135 1994 39.5571299805063 1995 38.9581147934405 1996 38.3346563242857 1997 37.6832748229627 1998 36.9650564195932 1999 36.1669969476886 2000 35.2045580144591 2001 34.1162605693357 2002 33.0335813005401 2003 31.9530044962087 2004 30.891065974927 2005 29.8985251567351 2006 29.0662595758166 2007 28.4804173096621 2008 28.1539549430262 2009 28.060917702977 2010 28.0901528943357 2011 28.1183882650388 2012 28.2124476560774 2013 28.4528936663698 2014 28.8188306381117 2015 29.2864976573898 2016 29.8366145913533 2017 30.4513409836696 2018 31.1069784964622 2019 31.748055139331 2020 32.2020073854056 2021 32.431183925479 2022 32.4651170591985 2023 32.2517849131596