Year % of total population 1960 42.4521657745093 1961 42.3017099803234 1962 42.2245222548294 1963 42.1232093731285 1964 42.0756715938212 1965 42.0970075144912 1966 42.1197041643382 1967 42.1320713663736 1968 42.1252793960326 1969 42.115348150471 1970 42.1109863636749 1971 42.0123973137417 1972 41.7963418539404 1973 41.545606886378 1974 41.3104015246471 1975 41.1000915142078 1976 40.9160553489963 1977 40.6244412305772 1978 40.2107667826927 1979 39.8312772163556 1980 39.5003381975471 1981 39.2972970550312 1982 39.1820672905327 1983 39.0092447629977 1984 38.7803922073062 1985 38.4949881734831 1986 38.2323331522298 1987 38.1271824703961 1988 38.1732326433438 1989 38.311148628694 1990 38.4964392263621 1991 38.7678071634523 1992 39.0626558356045 1993 39.2122252090487 1994 39.1476778273098 1995 38.8888062870066 1996 38.4861013778872 1997 37.8622902435447 1998 37.0609936173899 1999 36.1941912617258 2000 35.2406061055493 2001 34.2356953506007 2002 33.2318300544142 2003 32.2791043252836 2004 31.4321024862164 2005 30.727000178866 2006 30.1437091866371 2007 29.6558154157421 2008 29.302695663228 2009 29.0189318790711 2010 28.7358473643723 2011 28.5212185867199 2012 28.4282531163354 2013 28.4237501340174 2014 28.3948885310607 2015 28.2753516576484 2016 28.365853602124 2017 28.5860959589855 2018 28.68152980046 2019 28.7452694924885 2020 28.7396723302935 2021 28.6729624931736 2022 28.5507958905087 2023 28.299399244332