Year % of total population 1960 26.2392280261041 1961 26.2584522516185 1962 26.0358245787317 1963 25.8017368025271 1964 25.5786142597454 1965 25.3576975396534 1966 25.1644582970309 1967 24.9841411116096 1968 24.8193392916794 1969 24.6807493090679 1970 24.5493795259369 1971 24.4435555459378 1972 24.3560994147824 1973 24.2465285735584 1974 24.0783842710711 1975 23.8386527138307 1976 23.5436898386704 1977 23.2438786245753 1978 22.9420622642738 1979 22.6298928415577 1980 22.3715577533756 1981 22.1641726346767 1982 21.9763425925125 1983 21.7728375603489 1984 21.5389261121683 1985 21.29332116767 1986 21.0200308592999 1987 20.7144171230411 1988 20.4267000379895 1989 20.2024076984867 1990 20.0577502694109 1991 19.9745554856261 1992 19.8794482587662 1993 19.7406807651135 1994 19.5728147397073 1995 19.3770348402937 1996 19.1709896666928 1997 18.9774572813202 1998 18.8478591066208 1999 18.7750547502847 2000 18.7152735358576 2001 18.6538658604504 2002 18.5802717763657 2003 18.5040970931324 2004 18.4243391917787 2005 18.3477861733763 2006 18.2884889234338 2007 18.2462921051593 2008 18.2416249870445 2009 18.2746105151191 2010 18.3030070494363 2011 18.3117703431249 2012 18.3159073066943 2013 18.3056628243576 2014 18.2645944531063 2015 18.1869331011056 2016 18.0745056692548 2017 17.956176677331 2018 17.8354138790437 2019 17.701688275741 2020 17.5521513606696 2021 17.3733753734071 2022 17.1990019346205 2023 17.0411946065592