Year % of total population 1960 40.1310412332195 1961 40.2083028296822 1962 40.3235803693489 1963 40.4936055093087 1964 40.6550838187057 1965 40.7517590986976 1966 40.8070550784014 1967 40.8330693868048 1968 40.8315917169804 1969 40.8073110762161 1970 40.7606308478102 1971 40.6928696117749 1972 40.6172507913214 1973 40.5323931175884 1974 40.451963284282 1975 40.4030589943332 1976 40.3856889891845 1977 40.3971334906262 1978 40.432209232948 1979 40.4851020234545 1980 40.5627806020054 1981 40.6715812559519 1982 40.8097645262998 1983 40.9622643601417 1984 41.1187085085259 1985 41.2859962927139 1986 41.4648122216807 1987 41.6508702898385 1988 41.8374408452 1989 42.0041254917152 1990 42.1311228395526 1991 42.1925529874874 1992 42.1806105654072 1993 42.1108394568973 1994 41.9854061342165 1995 41.8110512269323 1996 41.5923313965658 1997 41.3290613691616 1998 41.0329137108331 1999 40.711298814305 2000 40.3656743906817 2001 39.9855199781713 2002 39.5616694503308 2003 39.1085132108787 2004 38.6306762954975 2005 38.1375817262272 2006 37.6666255139059 2007 37.2226510298912 2008 36.7945841608794 2009 36.3896712830994 2010 36.0115738483046 2011 35.6477424055023 2012 35.2827149403094 2013 34.9150626154469 2014 34.5519911185721 2015 34.1893703158829 2016 33.8427083414517 2017 33.527909194638 2018 33.2281203197735 2019 32.9324440492389 2020 32.642847758493 2021 32.3581190032574 2022 32.0762187607237 2023 31.7922020346082