Year % of total population 1960 69.295 1961 69.057 1962 68.985 1963 68.914 1964 68.842 1965 68.77 1966 68.69800000000001 1967 68.626 1968 68.554 1969 68.452 1970 68.26 1971 68.06700000000001 1972 67.87299999999999 1973 67.679 1974 67.48400000000001 1975 67.288 1976 67.092 1977 66.89500000000001 1978 66.69800000000001 1979 66.5 1980 66.238 1981 65.976 1982 65.713 1983 65.44800000000001 1984 65.18299999999999 1985 64.917 1986 64.65 1987 64.381 1988 64.112 1989 63.842 1990 63.572 1991 63.3 1992 62.751 1993 62.201 1994 61.646 1995 61.089 1996 60.527 1997 59.965 1998 59.399 1999 58.831 2000 58.259 2001 57.565 2002 56.499 2003 55.427 2004 54.349 2005 53.269 2006 52.185 2007 51.098 2008 50.009 2009 48.924 2010 47.837 2011 46.753 2012 45.67 2013 44.613 2014 43.577 2015 42.566 2016 41.579 2017 40.617 2018 39.681 2019 38.771 2020 37.888 2021 37.031 2022 36.201 2023 35.397000000000006