Year % of total population 1960 40.4966657057612 1961 41.8315304880697 1962 43.0154933671969 1963 44.0055167932857 1964 44.761761633638 1965 45.141768646615 1966 45.2013877812782 1967 45.1457115463419 1968 44.9766729416779 1969 44.7476644184153 1970 44.5325221679708 1971 44.3269426650671 1972 44.0884536711075 1973 43.7948850497195 1974 43.4295575714975 1975 42.9860128372347 1976 42.4909716281725 1977 41.9713843781256 1978 41.4840289042447 1979 41.1006055888116 1980 40.8155398750603 1981 40.6013488787279 1982 40.4488892493969 1983 40.3641288339275 1984 40.3412695013793 1985 40.3440691286093 1986 40.3585736600976 1987 40.3577391195864 1988 40.3029704855524 1989 40.2295225833564 1990 40.2011905331426 1991 40.1702884273257 1992 40.0826671573065 1993 39.9572048578646 1994 39.7781072742608 1995 39.5354458206325 1996 39.229182773354 1997 38.8288628824474 1998 38.3004789383585 1999 37.6392448343491 2000 36.874369234193 2001 36.0215913499146 2002 35.1251813521698 2003 34.2347887184327 2004 33.3687092081175 2005 32.5065818581219 2006 31.6458787798143 2007 30.8700495825353 2008 30.2261920822087 2009 29.696511717156 2010 29.2363201004871 2011 28.836105154761 2012 28.5408143042562 2013 28.4003665025922 2014 28.4136367865087 2015 28.5227759133108 2016 28.6743307982373 2017 28.8416271720228 2018 29.0881381624216 2019 29.4164411454935 2020 29.7700920460112 2021 30.070973508198 2022 30.2113376007802 2023 30.1955268469818