Year % of total population 1960 25.898848799242952 1961 25.935081154690913 1962 25.83564266471426 1963 25.698840461371653 1964 25.57453689770372 1965 25.4516057620152 1966 25.316868222878256 1967 25.179075564839515 1968 25.035722535173743 1969 24.88548798021197 1970 24.703194511306243 1971 24.506977411172286 1972 24.314203615548227 1973 24.113387218406498 1974 23.91455681522718 1975 23.712869474441124 1976 23.502204432530334 1977 23.267600592593485 1978 22.98718616298908 1979 22.671532914165752 1980 22.359206329453883 1981 22.057234734404936 1982 21.737725483710985 1983 21.405386380233594 1984 21.08097476891498 1985 20.776309889936503 1986 20.485018315110842 1987 20.202418729218937 1988 19.940797926215456 1989 19.681412832785885 1990 19.41644913560254 1991 19.12779578547114 1992 18.84627135106917 1993 18.597257308602238 1994 18.333960479287814 1995 18.052838830688206 1996 17.77509500542318 1997 17.515228508109498 1998 17.273884495122832 1999 17.048851493735146 2000 16.827326248712446 2001 16.606671871376427 2002 16.391283574211535 2003 16.182353460875916 2004 15.978665119111989 2005 15.795529716026419 2006 15.644381049498064 2007 15.528001273916026 2008 15.45698419997718 2009 15.426660176500018 2010 15.4115975783641 2011 15.395115536798588 2012 15.362409307576659 2013 15.323962318893113 2014 15.279265787474479 2015 15.232354866722119 2016 15.195754257911805 2017 15.17747999815004 2018 15.150957277056465 2019 15.103643766290006 2020 15.039242945878913 2021 14.962108647027927 2022 14.836812918078056 2023 14.692895489319662