Year % of total population 1960 43.0620163480956 1961 43.3849093103273 1962 43.7085939910994 1963 44.0401244090155 1964 44.3619983224939 1965 44.7492901995731 1966 45.148201930469 1967 45.3705420757774 1968 45.3980294211128 1969 45.2623612396197 1970 44.9934960043675 1971 44.4208986044941 1972 43.4748275706066 1973 42.349940771221 1974 41.1825892881887 1975 40.0339861074333 1976 38.9614523203264 1977 38.0027748047727 1978 37.1627502175805 1979 36.4330185046575 1980 35.7944814462417 1981 35.3010297287308 1982 34.9241848819872 1983 34.5789301397699 1984 34.2750481551939 1985 34.0241334974003 1986 33.8338190477037 1987 33.7177389192705 1988 33.6856413699359 1989 33.7332204788853 1990 33.8235876761268 1991 33.8816618884417 1992 33.7794650747561 1993 33.4735789025116 1994 33.0345855232329 1995 32.5110860223124 1996 31.9138814961849 1997 31.2416062392504 1998 30.543649026333 1999 29.8812004926802 2000 29.2738550718119 2001 28.6996221878051 2002 28.1004430564548 2003 27.2197533846489 2004 25.9258792658477 2005 24.5717196960709 2006 23.4025297109468 2007 22.4108917361504 2008 21.5465754516508 2009 20.721182073886 2010 20.4502636480452 2011 20.5523246460415 2012 20.1465051947464 2013 19.8996094867688 2014 20.2402957133688 2015 20.3692419733038 2016 20.1922306143108 2017 19.9932524913614 2018 19.9291083172336 2019 20.0682845571359 2020 20.298970739826 2021 20.3771974395624 2022 20.1867163689443 2023 19.882740568135