Year % of total population 1960 37.365608240959986 1961 37.442450648635585 1962 37.53958134152354 1963 37.75100906252541 1964 37.924127501970666 1965 37.99586229555169 1966 38.006132660539194 1967 37.9359909089703 1968 37.859648169143846 1969 37.79001552985324 1970 37.68389748992742 1971 37.568220199716166 1972 37.41757311240631 1973 37.25086137277071 1974 37.130060265826415 1975 37.01011933987682 1976 36.87433656631032 1977 36.62217883046742 1978 36.18930109628614 1979 35.75220390708815 1980 35.38726351936588 1981 35.06711434741958 1982 34.8111983841827 1983 34.535278844749975 1984 34.22608467422047 1985 33.93412670698622 1986 33.66634729523227 1987 33.445315376545366 1988 33.24174231925093 1989 33.05617748688039 1990 32.91668162254483 1991 32.76369647780418 1992 32.59620373812859 1993 32.42445915622157 1994 32.20566721136178 1995 31.938400738397704 1996 31.638803196361394 1997 31.296460223699754 1998 30.939381580758752 1999 30.585507329913273 2000 30.220672128371483 2001 29.836518859191255 2002 29.434511688242374 2003 29.042571460876967 2004 28.66122438933193 2005 28.278262898669592 2006 27.939284059969037 2007 27.670070255240113 2008 27.44749639973162 2009 27.25761157272298 2010 27.085961459623867 2011 26.935768568090065 2012 26.809966225525862 2013 26.700405755466175 2014 26.591331815696545 2015 26.46917676035287 2016 26.33827628689017 2017 26.21099001180987 2018 26.065399058851607 2019 25.893258605041247 2020 25.698201981482576 2021 25.494819211241136 2022 25.27767509631814 2023 25.019820523098613