Year % of total population 1960 58.5791520957561 1961 58.2861461171662 1962 57.8385167960802 1963 57.2285497342445 1964 56.4015566815816 1965 55.2567529443268 1966 54.0646199839025 1967 53.2406317332682 1968 52.8026954131444 1969 52.5111023760339 1970 52.2607866604459 1971 52.0867108431839 1972 52.0243834476546 1973 52.0875944864384 1974 52.1298225537719 1975 51.9881083800288 1976 51.7798837031888 1977 51.6791124667719 1978 51.5939753244672 1979 51.5022516622382 1980 51.494209653307 1981 51.5686979482857 1982 51.7394605280121 1983 52.01252373292 1984 52.2496040957112 1985 52.1119214637823 1986 51.6497696787164 1987 51.1989855867147 1988 50.8803750710362 1989 50.6742774287982 1990 50.4625328396094 1991 50.2601766099505 1992 50.1740644948157 1993 50.2374458755601 1994 50.4809655790421 1995 50.9891250464742 1996 51.747545401311 1997 52.6457032411537 1998 53.6777381700244 1999 54.8611885182535 2000 56.1618936201468 2001 57.5073044843182 2002 58.8346588158415 2003 60.1391872500845 2004 61.4428342344221 2005 62.7388296451674 2006 64.2074360568765 2007 65.8541611559826 2008 67.4063398865482 2009 68.74027681879 2010 69.8456334724932 2011 70.7368727474726 2012 71.4251063439985 2013 71.9479297678226 2014 72.4288401825607 2015 72.8760600759444 2016 73.229206223411 2017 73.5130449875329 2018 73.7357021222726 2019 73.8554195374504 2020 73.8265835727532 2021 73.73793645695 2022 73.5375257499709 2023 73.2225061729698