Year % of total population 1960 41.4153545830148 1961 41.9234880647884 1962 42.3874290947468 1963 42.8638377103853 1964 43.4290373010136 1965 43.9743786053341 1966 44.4009153085209 1967 44.7887122576797 1968 45.1258808653194 1969 45.3526761745652 1970 45.4523596349936 1971 45.3501284499297 1972 45.0630945873203 1973 44.6610698139817 1974 44.1781384636379 1975 43.5854233500774 1976 42.9308561209233 1977 42.3556024996514 1978 41.8118611766006 1979 41.2281667653091 1980 40.6245990486742 1981 40.0231324108984 1982 39.4283112521061 1983 38.9034260629623 1984 38.456615456371 1985 38.0478004214605 1986 37.6622229821955 1987 37.2889829619753 1988 36.9382312042332 1989 36.6119202061208 1990 36.2830182487298 1991 35.9886967233268 1992 35.8328808243249 1993 35.7579434760083 1994 35.6514811820312 1995 35.4850536309483 1996 35.2108102431448 1997 34.8524014811223 1998 34.4548385506762 1999 33.987155806762 2000 33.4070641469563 2001 32.754616382117 2002 32.094971521772 2003 31.4418336742704 2004 30.8083878357725 2005 30.2134625492601 2006 29.6230137595433 2007 28.9430594534842 2008 28.1852035850471 2009 27.4110743767956 2010 26.6078153667879 2011 25.8478036406711 2012 25.1484246962752 2013 24.4485200652404 2014 23.7916419319077 2015 23.2731406903948 2016 22.8462385585591 2017 22.3904709323949 2018 21.8973375038009 2019 21.3741122684737 2020 20.8331833860409 2021 20.2996115740226 2022 19.8397666812738 2023 19.427041204639