Year % of total population 1960 29.988812821458517 1961 30.060100090387795 1962 29.961609868733085 1963 29.806157182490047 1964 29.693440837071567 1965 29.62638907772107 1966 29.496470014353545 1967 29.335429696862366 1968 29.200854324898447 1969 29.033270147698747 1970 28.838438307581832 1971 28.61190145929795 1972 28.363922772336235 1973 28.086369161551104 1974 27.789008194939804 1975 27.46439900946507 1976 27.116251460461818 1977 26.765801105570137 1978 26.40609653712968 1979 26.04062421969395 1980 25.696558619870178 1981 25.39705272179161 1982 25.11586168719361 1983 24.81328427722558 1984 24.50671300984443 1985 24.20258601865375 1986 23.892988677376895 1987 23.603074499242517 1988 23.348391984347497 1989 23.113623566744593 1990 22.903300799858552 1991 22.706795567302308 1992 22.524837357671164 1993 22.35602257792469 1994 22.168893979025352 1995 21.95987605568995 1996 21.7486741539766 1997 21.548635121942752 1998 21.357874811604454 1999 21.172392697084156 2000 20.981845563681134 2001 20.781157778477233 2002 20.575108790313514 2003 20.36221007288382 2004 20.14019303277033 2005 19.913308842760344 2006 19.695253385339548 2007 19.496603027354418 2008 19.327116671083687 2009 19.174322883416327 2010 19.027099313418567 2011 18.8902821584755 2012 18.74879179675335 2013 18.606043715742533 2014 18.461629985653936 2015 18.318649316785784 2016 18.18521052991706 2017 18.064238538304377 2018 17.932731351106344 2019 17.782165271629548 2020 17.617229477085786 2021 17.436910872611826 2022 17.225843550979075 2023 16.99594215669544