Year % of total population 1960 17.772011711348437 1961 18.07485526101633 1962 18.38388360670162 1963 18.698496526243947 1964 19.020358002239497 1965 19.346370353523536 1966 19.679001157213317 1967 20.01713978798534 1968 20.361979919571663 1969 20.710381271207183 1970 21.066761337926458 1971 21.429666868375886 1972 21.80107905955271 1973 22.17827413056214 1974 22.56479910805552 1975 22.96282052882185 1976 23.373989747070897 1977 23.78718760935339 1978 24.213033882524154 1979 24.655763067742292 1980 25.120064406264337 1981 25.603642510050335 1982 26.111370198350293 1983 26.642006855514637 1984 27.196195220480856 1985 27.767502971515732 1986 28.360607502350128 1987 28.972965880919933 1988 29.607005922335915 1989 30.261864095681496 1990 30.945856328054166 1991 31.65995181984104 1992 32.39063136671049 1993 32.90193676470335 1994 33.44339709700974 1995 34.016640500232675 1996 34.61683510095355 1997 35.23846471553903 1998 35.88428667414511 1999 36.545597775674324 2000 37.23075845233418 2001 37.94200924665256 2002 38.148343765796014 2003 38.242380962790776 2004 38.342014168624885 2005 38.44376493752845 2006 38.543004190758914 2007 38.642881915554405 2008 38.75363553584284 2009 38.87061765139832 2010 38.99721908939116 2011 39.13308707777789 2012 39.28123956628086 2013 39.43926609849498 2014 39.60995831542164 2015 39.79502411388191 2016 39.992950377851756 2017 40.20443122327573 2018 40.43188946579644 2019 40.6112598669561 2020 40.83718032647345 2021 41.12007544700629 2022 41.401607151768104 2023 41.61886790655678