Year % of total population 1960 31.1162718095194 1961 30.978751758437 1962 30.8310830744831 1963 30.6841967032698 1964 30.5438191063246 1965 30.402439758188 1966 30.2487229901412 1967 30.0925866217024 1968 29.9432253862993 1969 29.8161241116447 1970 29.7172637318956 1971 29.6564488381245 1972 29.6308497117393 1973 29.6526490435127 1974 29.7392986639616 1975 29.8600839862065 1976 30.0064544823582 1977 30.1667697345714 1978 30.3256586825057 1979 30.4869114252418 1980 30.6423461860258 1981 30.77572543705 1982 30.8801489982181 1983 30.9572559776673 1984 31.0037490701741 1985 31.0110765925784 1986 30.9722416925682 1987 30.890024070159 1988 30.7641438755437 1989 30.5949084283413 1990 30.4039445969413 1991 30.1980957212797 1992 29.9729814917119 1993 29.7415810060055 1994 29.5108852477345 1995 29.2814736747524 1996 29.0505618609344 1997 28.8213354430812 1998 28.5985102887007 1999 28.3864423108692 2000 28.1802131806071 2001 27.9635039480871 2002 27.7328473929068 2003 27.4942108965076 2004 27.2480435226372 2005 26.9902147785386 2006 26.7224838516436 2007 26.4535033713104 2008 26.1772159938644 2009 25.8961479735009 2010 25.6397444358013 2011 25.4191748509299 2012 25.2279686735182 2013 25.0575117846874 2014 24.8909505962578 2015 24.7292121561043 2016 24.5763205280432 2017 24.4068430876801 2018 24.1931513494201 2019 23.9395441152544 2020 23.6563980592251 2021 23.3567371619625 2022 23.0533315543961 2023 22.7340998635816