Year % of total population 1960 50.863752019846196 1961 50.046162591633816 1962 49.215722083883556 1963 48.38245958589604 1964 47.54431670510411 1965 46.7635398500038 1966 45.983116741556714 1967 45.20366855400655 1968 44.42345241177086 1969 43.64780141886121 1970 42.877266626021026 1971 42.115013362680266 1972 41.363161138946275 1973 40.63422325371932 1974 39.91057153920909 1975 39.18684670224152 1976 38.46676005882261 1977 37.74590452276824 1978 37.026965044853355 1979 36.31468479736095 1980 35.61208462665195 1981 34.94818023279889 1982 34.311392819230534 1983 33.69176675129248 1984 33.07691390400919 1985 32.46648667842196 1986 31.869283165177606 1987 31.282242451436105 1988 30.70193270512497 1989 30.131318145381854 1990 29.572365180727232 1991 29.038652103633645 1992 28.52473555325256 1993 28.02363004387338 1994 27.51638913472798 1995 27.01446435873409 1996 26.535738679930265 1997 26.048844466698235 1998 25.56805070881827 1999 25.10415644131591 2000 24.6452423663369 2001 24.278691440674184 2002 23.942331841351862 2003 23.613111414577812 2004 23.29598439115173 2005 22.98378082699652 2006 22.674383161671688 2007 22.36889190962362 2008 22.070200972410365 2009 21.77912631428333 2010 21.495728058768794 2011 21.207829918165405 2012 20.92876290127201 2013 20.65508802965565 2014 20.383643396012687 2015 20.115278098017594 2016 19.85196914567087 2017 19.596060050385844 2018 19.352308828967878 2019 19.109803629400794 2020 18.861640532891062 2021 18.615200497175866 2022 18.366860903693308 2023 18.115994603719358