Year % of total population 1960 37.64787126600546 1961 38.112228997548854 1962 38.589065646320805 1963 39.07783172647608 1964 39.58986272257754 1965 40.10154268625848 1966 40.60482011060141 1967 41.07397446394288 1968 41.563753207298696 1969 42.05624005173615 1970 42.54182654236699 1971 43.05846979285935 1972 43.58079309796442 1973 44.01994689051661 1974 44.59480443889377 1975 45.19402110444284 1976 45.792017048482585 1977 46.351476275567194 1978 46.902713386026065 1979 47.41104795397781 1980 47.87712958248721 1981 48.37212304240966 1982 48.89392224726942 1983 49.270080150357245 1984 49.63840672127932 1985 50.02916869095657 1986 50.444115818809 1987 50.86126757318492 1988 51.26021469327154 1989 51.65343725281014 1990 52.05251788210954 1991 52.326784995730335 1992 52.497270392724715 1993 52.65017122410893 1994 52.87526194586318 1995 53.08424916879569 1996 53.264848245293905 1997 53.48443099337757 1998 53.68119025647886 1999 53.894874546315904 2000 54.117113962499715 2001 54.33772943959349 2002 54.5395892513945 2003 54.76605135626382 2004 55.03809500959625 2005 55.33692325195311 2006 55.61351286761804 2007 55.87990676987665 2008 56.17455647306502 2009 56.45959208257178 2010 56.64086806345267 2011 56.71565888067352 2012 56.83718118781738 2013 57.046243880666424 2014 57.29482485363293 2015 57.55733228730741 2016 57.822301112058106 2017 58.10786534827916 2018 58.378631327258134 2019 58.60835031311819 2020 58.76204142305578 2021 58.90330848140226 2022 59.165775490264025 2023 59.480618272565515