Year % of total population 1960 73.402 1961 72.759 1962 72.105 1963 71.44200000000001 1964 70.768 1965 70.087 1966 69.396 1967 68.696 1968 67.987 1969 67.271 1970 66.54599999999999 1971 65.729 1972 64.896 1973 64.056 1974 63.206 1975 62.348 1976 61.481 1977 60.609 1978 59.729 1979 58.842 1980 57.956 1981 57.193 1982 56.426 1983 55.655 1984 54.881 1985 54.107 1986 53.329 1987 52.55 1988 51.768 1989 50.988 1990 50.206 1991 49.424 1992 48.186 1993 46.891 1994 45.598 1995 44.312 1996 43.031 1997 41.763 1998 40.504 1999 39.258 2000 38.023 2001 37.078 2002 36.144 2003 35.22 2004 34.306 2005 33.406000000000006 2006 32.516999999999996 2007 31.64 2008 30.775000000000006 2009 29.924999999999997 2010 29.087999999999994 2011 28.391000000000005 2012 27.724999999999994 2013 27.069999999999993 2014 26.423000000000002 2015 25.787000000000006 2016 25.159999999999997 2017 24.552999999999997 2018 23.964 2019 23.393 2020 22.840000000000003 2021 22.304000000000002 2022 21.786 2023 21.284000000000006