Year % of total population 1960 26.461416251850284 1961 26.896470894487738 1962 27.318619776920176 1963 27.740844044330014 1964 28.168051398419475 1965 28.596564120199286 1966 29.042795570356173 1967 29.508607482280414 1968 29.995162001916587 1969 30.50124363653174 1970 30.92931527032805 1971 31.232832684701194 1972 31.552868590652274 1973 31.883923509153465 1974 32.23574910072511 1975 32.60983350303881 1976 33.016222328314626 1977 33.430975833689956 1978 33.86005710155591 1979 34.33640006674254 1980 34.879344397635954 1981 35.10023699561987 1982 35.403876227990736 1983 35.734746423815324 1984 36.10209404442155 1985 36.508176367012254 1986 36.95939874343328 1987 37.45171333586681 1988 37.97201402448651 1989 38.51961722491616 1990 38.92185929324795 1991 39.01793840897705 1992 39.12808446571068 1993 39.24703116721757 1994 39.37967483092003 1995 39.53416717376403 1996 39.723114380707955 1997 39.934368352267846 1998 40.16777140094043 1999 40.42363399066235 2000 40.57662240998942 2001 40.5302083355132 2002 40.49478006602272 2003 40.47420162548932 2004 40.46306223031802 2005 40.468007358178355 2006 40.503136075094034 2007 40.55771396044687 2008 40.63443373474621 2009 40.723672165155136 2010 40.78079876745898 2011 40.820140740361836 2012 40.874273640752115 2013 40.96051923509084 2014 41.08014956765891 2015 41.2321010978478 2016 41.26149640146228 2017 41.314367919741095 2018 41.423644571472536 2019 41.57967117338022 2020 41.80361255979466 2021 42.11226698636325 2022 42.40521159609542 2023 42.65911184682249