Year % of total population 1960 22.14326349447897 1961 22.57700730172007 1962 23.02329220896884 1963 23.48130364888796 1964 23.947879842260786 1965 24.417155096477416 1966 24.881300334703134 1967 25.25695081931525 1968 25.636863049290238 1969 26.037904579557733 1970 26.424962017952904 1971 26.7717314770602 1972 27.094765379706885 1973 27.40169388785736 1974 27.619224274525887 1975 27.809211921371922 1976 28.018461352285392 1977 28.181252208426372 1978 28.33811523768505 1979 28.49741046242722 1980 28.66605661366969 1981 28.86528157553046 1982 29.075251967499938 1983 29.299068883132446 1984 29.533227153608575 1985 29.76459294796066 1986 29.99285416322649 1987 30.39483286911701 1988 30.810598459977 1989 31.209433596309193 1990 31.58691089338564 1991 31.943032225450942 1992 32.27661424310367 1993 32.598801599565974 1994 32.911647066686555 1995 33.20111752891738 1996 33.53271568204011 1997 33.76567611393459 1998 33.985270518979874 1999 34.208315428434155 2000 34.459670914567766 2001 34.70444070685251 2002 34.91212171609759 2003 35.11724691452404 2004 35.33865798316979 2005 35.56032409119653 2006 35.80196080589579 2007 36.05718209334983 2008 36.344373397183936 2009 36.63267762171985 2010 36.89828979912671 2011 37.13983544982048 2012 37.37079484866076 2013 37.59784789596267 2014 37.82249269158046 2015 38.044097757036404 2016 38.259760265422855 2017 38.46854478008166 2018 38.67702272703732 2019 38.88279444652553 2020 39.09482359293741 2021 39.31228846775369 2022 39.55370278728573 2023 39.82153545879193