Year % of total population 1960 12.2102821053074 1961 12.4031984206473 1962 12.5951908600503 1963 12.7628907432785 1964 12.965663863153 1965 13.1654297837876 1966 13.3583329457451 1967 13.5583206830007 1968 13.7398082065249 1969 13.9070172173585 1970 14.054812662933 1971 14.1916416934735 1972 14.3190861085083 1973 14.449845052543 1974 14.6300452525497 1975 14.8485150838216 1976 15.0173434653996 1977 15.1680636840075 1978 15.3180206101677 1979 15.4295254270928 1980 15.3827696534834 1981 15.0850813602629 1982 14.7037974643419 1983 14.341886809426 1984 14.1310335133169 1985 14.1611667161568 1986 14.318526740598 1987 14.5250313986508 1988 14.7246672676438 1989 14.8647585394134 1990 14.9427919646598 1991 14.95112974587 1992 14.9139952452656 1993 14.9212409052054 1994 15.001880820857 1995 15.1170734748695 1996 15.2197444069464 1997 15.3045031606886 1998 15.3712100334735 1999 15.4002817912534 2000 15.413033147977 2001 15.4347425760068 2002 15.433002037878 2003 15.4469696447238 2004 15.7088972003128 2005 16.1893814836926 2006 16.656826238438 2007 17.0045481934175 2008 17.2586925227657 2009 17.509070997852 2010 17.6356410013884 2011 17.7144340329413 2012 17.9292665822542 2013 18.1800272396884 2014 18.369845164421 2015 18.4446059732568 2016 18.4850626164191 2017 18.5968996178003 2018 18.7505079598044 2019 18.9301120801555 2020 19.1494297623302 2021 19.4411573442163 2022 19.8070286456344 2023 20.2099674398609