Year % of total population 1960 40.71990164594391 1961 40.97439304293791 1962 41.225092077377916 1963 41.472424443240925 1964 41.64263634916752 1965 41.7111021913422 1966 41.741160470767696 1967 41.74359214448812 1968 41.72564084554768 1969 41.688659768134954 1970 41.62097611398606 1971 41.551757345914574 1972 41.477902324507 1973 41.381934954122485 1974 41.28123759398088 1975 41.15813943996063 1976 41.01918432739768 1977 40.87134912903464 1978 40.711292425995985 1979 40.55662277343421 1980 40.40772680143664 1981 40.269921845869774 1982 40.14842188967871 1983 40.03805011946091 1984 39.94402006125677 1985 39.84413002011362 1986 39.726320517816916 1987 39.590895185527614 1988 39.43282199904241 1989 39.26273650811729 1990 39.0775132194899 1991 38.8784035928731 1992 38.69582732485372 1993 38.507657173139116 1994 38.28055776758483 1995 38.01726025144094 1996 37.715231171728206 1997 37.389529821057344 1998 37.04816923866528 1999 36.68969693827355 2000 36.3143301449696 2001 35.93829624324738 2002 35.58717639556401 2003 35.2395498454667 2004 34.86648875613123 2005 34.4802113590608 2006 34.086556892054894 2007 33.692987677786185 2008 33.301130612003206 2009 32.89853931996009 2010 32.48149103325882 2011 32.05457978474969 2012 31.626365249518532 2013 31.19806845986141 2014 30.752572553447955 2015 30.291132805887592 2016 29.81871160345394 2017 29.331267564972535 2018 28.852085702050577 2019 28.387990951952595 2020 27.933668790850124 2021 27.526201406486074 2022 27.156676165174254 2023 26.76979785251538