Year % of total population 1960 4.47218766179026 1961 4.39975292254516 1962 4.33991647561238 1963 4.28907324156895 1964 4.24537094476301 1965 4.20596138543709 1966 4.16927129970344 1967 4.12374050927009 1968 4.06797535132753 1969 4.01266715861481 1970 3.95810769417913 1971 3.9043136056097 1972 3.8529330813075 1973 3.80678063262599 1974 3.76503038620212 1975 3.73147889292703 1976 3.71291669535133 1977 3.70991977194683 1978 3.71785120707626 1979 3.73152781780335 1980 3.74955822465808 1981 3.77343565684433 1982 3.80160158667132 1983 3.82949832421875 1984 3.85516253757309 1985 3.87846331130694 1986 3.89898017403375 1987 3.92324268263899 1988 3.95274243496548 1989 3.9812313057926 1990 4.00903948144438 1991 4.03698368333152 1992 4.06597876682735 1993 4.09755510273787 1994 4.13358441822173 1995 4.1724521522782 1996 4.21201500180937 1997 4.25737175985645 1998 4.31042601399348 1999 4.36654409718374 2000 4.4204780274488 2001 4.46687702209532 2002 4.50180184712797 2003 4.52464338218692 2004 4.534765063081 2005 4.52566065750188 2006 4.48340230071126 2007 4.42205937589017 2008 4.35079762618148 2009 4.27729076050845 2010 4.21960828516863 2011 4.17527021585615 2012 4.14735744759135 2013 4.14421642686126 2014 4.17159350290002 2015 4.17888332919129 2016 4.15869044420562 2017 4.15303574974304 2018 4.16213796344614 2019 4.18710685148031 2020 4.21094893749168 2021 4.20782005514465 2022 4.19541721609029 2023 4.21961814216303