Year % of total population 1960 21.2142866237172 1961 21.4909329820871 1962 21.7289558921001 1963 21.9288496188925 1964 22.1234911379489 1965 22.3228742790954 1966 22.4787283061743 1967 22.5500991627416 1968 22.5249335032406 1969 22.4059134619648 1970 22.2194718013096 1971 21.9551101630111 1972 21.5564631825924 1973 21.1792569003339 1974 20.8692979535384 1975 20.53912372249 1976 20.1949203262815 1977 19.8473761850466 1978 19.5439098897995 1979 19.1838967079232 1980 18.775859746358 1981 18.4423811914737 1982 18.1321571420744 1983 17.7949625178381 1984 17.4819802640662 1985 17.2166039960051 1986 17.0127930032322 1987 16.9273992548441 1988 16.9972043102894 1989 17.1756656736057 1990 17.3857393712797 1991 17.5990590025582 1992 17.8217493027105 1993 18.0627556261383 1994 18.2857078898179 1995 18.4577888824698 1996 18.5779819289136 1997 18.6953513467006 1998 18.8186938040269 1999 18.927747505814 2000 18.9629684042348 2001 18.9321460987491 2002 18.8838617441763 2003 18.7905656677778 2004 18.6765285716002 2005 18.5376441699051 2006 18.3944445796866 2007 18.2452067597686 2008 18.0533342338 2009 17.8481043168069 2010 17.6671048051598 2011 17.3709875995261 2012 17.0781468361778 2013 16.9229126136718 2014 16.7532116039452 2015 16.5662552741227 2016 16.3563617787576 2017 16.1887192731633 2018 16.0999189028693 2019 16.0251333525815 2020 15.9809771422725 2021 15.9137585031619 2022 15.7999008645782 2023 15.6897677419847