Year % of total population 1960 39.7482420832152 1961 40.0158679650706 1962 40.3304215393334 1963 40.6898452178622 1964 41.0643700593424 1965 41.4691250636623 1966 41.8600004316292 1967 42.1652779906778 1968 42.3708639033148 1969 42.4844100155609 1970 42.5342287706198 1971 42.5227268915297 1972 42.4512482991784 1973 42.331108609885 1974 42.1601966288762 1975 41.940881266955 1976 41.6843727588308 1977 41.3956212878516 1978 41.0866385308351 1979 40.7611724420572 1980 40.4140900426339 1981 40.0413070822588 1982 39.6527351916317 1983 39.2543662420948 1984 38.8355362821279 1985 38.3745352164627 1986 37.8680785290718 1987 37.3456280569366 1988 36.820874334381 1989 36.2957566272302 1990 35.7578283129467 1991 35.2179951699015 1992 34.6797787588542 1993 34.1281649093116 1994 33.5780992781131 1995 33.0397746419527 1996 32.5224438778193 1997 32.0232254424488 1998 31.532679468303 1999 31.0509721894719 2000 30.6120751289769 2001 30.2370891591003 2002 29.8904893579276 2003 29.5491311393004 2004 29.22273755226 2005 28.9371160924099 2006 28.6825673004558 2007 28.4602333111607 2008 28.26978404013 2009 28.0756308812162 2010 27.8719609703903 2011 27.6736541283578 2012 27.4798357119445 2013 27.2781654669592 2014 27.0780193892504 2015 26.8757621605868 2016 26.6614853832716 2017 26.4374424838006 2018 26.2042610175391 2019 25.9624659842084 2020 25.7189360206748 2021 25.4764856786637 2022 25.2064862015063 2023 24.8820533770582