Year % of total population 1960 31.19462185472156 1961 31.986381013276354 1962 32.77047258858584 1963 33.59032741891879 1964 34.475286144875 1965 35.11273350914635 1966 35.771045177070214 1967 36.479133551984795 1968 37.203834519962285 1969 37.92405876006907 1970 38.74571698356405 1971 40.95892245193451 1972 44.17711340740992 1973 47.66489444288576 1974 51.48335662848288 1975 55.72922433093351 1976 49.63055530857515 1977 44.77202072988419 1978 49.401254317311185 1979 55.04961125560099 1980 54.76427791997981 1981 54.465843601823714 1982 54.55789700315915 1983 52.92849349370291 1984 51.03370951314944 1985 49.1239482451383 1986 47.044235053702984 1987 45.05849531241245 1988 43.3883652073906 1989 39.49726875775422 1990 35.96652475164872 1991 32.72789899676388 1992 32.48397303684219 1993 32.299499632868574 1994 32.16192610150242 1995 32.01775919022942 1996 31.86067373730338 1997 31.72401267811404 1998 32.54535290649146 1999 33.45605432445024 2000 34.40891423080181 2001 35.41066709195297 2002 37.731369974718135 2003 37.96697616568257 2004 38.112467066844715 2005 38.27980092370436 2006 38.51833442658517 2007 38.66479347173408 2008 38.91856822543029 2009 39.29862546668592 2010 39.838724528604025 2011 40.35273344835023 2012 40.213972169057364 2013 37.508978488782326 2014 34.7260955810187 2015 34.8292842251998 2016 36.425240136841694 2017 38.16992653110397 2018 40.082936204457894 2019 41.6277017253996 2020 42.812254378171836 2021 43.53244474738276 2022 44.32187031113865 2023 45.22573137863215