Year % of total population 1960 26.49244380925406 1961 26.835495846808758 1962 27.16395134871223 1963 27.50642147787 1964 27.86958475038187 1965 28.25501973345323 1966 28.58760035241048 1967 28.93970516807662 1968 29.31827629991234 1969 29.7094800779625 1970 30.086391635776483 1971 30.234447895624612 1972 30.3513135309757 1973 30.488334261270175 1974 30.646538572364218 1975 30.827962511976704 1976 30.96778865771601 1977 31.092296552426188 1978 31.223464339906236 1979 31.347597603580876 1980 31.484669745397245 1981 31.612576588440096 1982 31.75274932158572 1983 31.911901923462555 1984 32.088166206683965 1985 32.272545814638995 1986 32.47577452119323 1987 32.715882814481525 1988 32.91761031046782 1989 33.11888339441845 1990 33.311724294226785 1991 33.42377208185745 1992 33.49869586523944 1993 33.592876366382185 1994 33.71786540200984 1995 33.861522324899354 1996 33.9809149811277 1997 34.09167148977635 1998 34.21583857654619 1999 34.35178728466712 2000 34.4701885613692 2001 34.555873177701756 2002 34.67489274978705 2003 34.80087535718364 2004 34.92475308359727 2005 35.05935512684283 2006 35.17200018715404 2007 35.27975889934321 2008 35.38399449141112 2009 35.521753814849944 2010 35.67848732453298 2011 35.88495216502662 2012 36.03270594270052 2013 36.175904839196654 2014 36.31712692684906 2015 36.46464566674301 2016 36.61486334630603 2017 36.79500259635218 2018 36.98961617830729 2019 37.10526501087243 2020 37.18805296939994 2021 37.43054829356908 2022 37.72582843493055 2023 37.76668439196149