Year % of total population 1960 2.92008764984256 1961 2.90399552093879 1962 2.88128443026862 1963 2.85630372239481 1964 2.8298304683323 1965 2.80294635117782 1966 2.77916022889489 1967 2.75988694149307 1968 2.74537013962429 1969 2.73623057973423 1970 2.73193475354971 1971 2.73203067649013 1972 2.73354396275506 1973 2.7360321125214 1974 2.74139651006731 1975 2.74936488353141 1976 2.76035222535748 1977 2.76964271498976 1978 2.77648226408261 1979 2.78680668061127 1980 2.80768864303183 1981 2.83397818499468 1982 2.85684290319461 1983 2.87614541020352 1984 2.88955461365855 1985 2.89836459428105 1986 2.9081286096133 1987 2.91759371254158 1988 2.92332071599315 1989 2.92586786702898 1990 2.92446509304329 1991 2.92304306510892 1992 2.92141175271714 1993 2.91766932076779 1994 2.91253057299789 1995 2.9066395722172 1996 2.89718243731084 1997 2.88524672122595 1998 2.86962960805065 1999 2.84598010709894 2000 2.82055235315092 2001 2.80350940096126 2002 2.79095483881045 2003 2.77488305799712 2004 2.75738387802976 2005 2.74138766568266 2006 2.72789582070683 2007 2.71466904956662 2008 2.70021329953365 2009 2.68265648012352 2010 2.65917858162725 2011 2.63112341317521 2012 2.60526230999014 2013 2.59011154522437 2014 2.5838209423975 2015 2.57693876845108 2016 2.56951489434989 2017 2.56929598307506 2018 2.57827668775889 2019 2.59259393781103 2020 2.6001260045508 2021 2.58768007254527 2022 2.56835416022227 2023 2.57148537316511