Year % of total population 1960 2.73853148454204 1961 2.74950310551446 1962 2.75934413186506 1963 2.76824817728397 1964 2.77681321758611 1965 2.78574658291704 1966 2.79478583624711 1967 2.80398201312428 1968 2.81307660407372 1969 2.82205746512214 1970 2.82998081256744 1971 2.83759540634906 1972 2.84611549120646 1973 2.85451818912254 1974 2.92526189099418 1975 3.05510279666313 1976 3.1826515343938 1977 3.31099467123973 1978 3.43779997444181 1979 3.55740806007293 1980 3.6672045288974 1981 3.76046986858649 1982 3.83750807005852 1983 3.91785439996581 1984 3.93677971043837 1985 3.89668424345339 1986 3.87134693693896 1987 3.86031391432865 1988 3.85882308861961 1989 3.85848407373176 1990 3.85632349316342 1991 3.85178711182646 1992 3.83271119036688 1993 3.77524429549216 1994 3.70695320646912 1995 3.66983334198765 1996 3.65101206345235 1997 3.63226479534579 1998 3.61173848187826 1999 3.58872437431033 2000 3.56209466317088 2001 3.53188804349185 2002 3.49837162438474 2003 3.42191607124501 2004 3.3120997379398 2005 3.2138056141771 2006 3.12523739345782 2007 3.04716996900929 2008 2.98062417143471 2009 2.92406924161888 2010 2.87419184163322 2011 2.82977982316191 2012 2.78661377360852 2013 2.73292077466404 2014 2.66416143487105 2015 2.59820379041011 2016 2.54796132669286 2017 2.50980448151474 2018 2.4824579826992 2019 2.46818953530525 2020 2.45499699882867 2021 2.43613858095079 2022 2.42607886497817 2023 2.43773547076845