Year % of total population 1960 39.38707748348008 1961 39.54491187339207 1962 39.68153575983173 1963 39.834297647241314 1964 39.969986661571944 1965 40.0827094414461 1966 40.18505588255541 1967 40.28449036837502 1968 40.38500920601032 1969 40.479814098986346 1970 40.575967711219754 1971 40.684260801049 1972 40.803685321008274 1973 40.91519979429065 1974 41.00081578548088 1975 41.082303052296574 1976 41.173888824220704 1977 41.255182518991404 1978 41.31749237102473 1979 41.38962884544452 1980 41.459845437009356 1981 41.52485847778925 1982 41.60576012143339 1983 41.68964846909874 1984 41.770471913489885 1985 41.84322655173847 1986 41.90065554593836 1987 41.94742325627457 1988 41.978267074029986 1989 41.98774233127082 1990 42.0086253385142 1991 41.974626234137624 1992 41.94645515105742 1993 41.94180409637715 1994 41.865940999615674 1995 41.755500126573104 1996 41.71294690993986 1997 41.673948724987085 1998 41.58897309876269 1999 41.48385351663289 2000 41.37724513910472 2001 41.268956355378755 2002 41.18750724188036 2003 41.12800073414206 2004 41.060689993609905 2005 40.9889949130292 2006 40.91174435629445 2007 40.85255293996482 2008 40.82152166654044 2009 40.7909589085592 2010 40.75716662675926 2011 40.72866033449601 2012 40.710664383065094 2013 40.70149071468493 2014 40.680720078665466 2015 40.629974650964336 2016 40.547934930152245 2017 40.44204823170539 2018 40.32117349104514 2019 40.17348385036557 2020 40.00057466386073 2021 39.82329004622807 2022 39.759924595455 2023 39.51941779226993