Year | Value | 2022 | 49.277340254076 | 2021 | 49.27622059911 | 2020 | 49.278568651405 | 2019 | 49.283105052242 | 2018 | 49.289553138412 | 2017 | 49.296919917184 | 2016 | 49.303172302614 | 2015 | 49.309185495876 | 2014 | 49.317670325863 | 2013 | 49.329913866249 | 2012 | 49.344236208971 | 2011 | 49.359762292809 | 2010 | 49.376043059327 | 2009 | 49.393889417671 | 2008 | 49.412497755606 | 2007 | 49.431365135144 | 2006 | 49.451785040036 | 2005 | 49.474620433698 | 2004 | 49.49994707069 | 2003 | 49.530664401172 | 2002 | 49.564826186967 | 2001 | 49.598601330016 | 2000 | 49.632825173917 | 1999 | 49.666895755132 | 1998 | 49.700872968202 | 1997 | 49.736926136635 | 1996 | 49.775629149225 | 1995 | 49.815405019687 | 1994 | 49.853665586469 | 1993 | 49.891548837071 | 1992 | 49.933113626903 | 1991 | 49.97925796559 | 1990 | 50.031025077151 | 1989 | 50.088139895208 | 1988 | 50.1493727589 | 1987 | 50.21349185782 | 1986 | 50.281803107947 | 1985 | 50.354470702255 | 1984 | 50.430128326552 | 1983 | 50.507211443965 | 1982 | 50.584931399379 | 1981 | 50.664345890885 | 1980 | 50.74382283223 | 1979 | 50.819596833285 | 1978 | 50.89286344319 | 1977 | 50.964594594259 | 1976 | 51.034569834739 | 1975 | 51.102229292385 | 1974 | 51.173089064941 | 1973 | 51.253631372369 | 1972 | 51.342889354686 | 1971 | 51.439129068006 | 1970 | 51.537804933413 | 1969 | 51.638358236519 | 1968 | 51.742209176465 | 1967 | 51.851729380667 | 1966 | 51.966530385493 | 1965 | 52.086110752027 | 1964 | 52.21124772924 | 1963 | 52.341187386811 | 1962 | 52.477292251179 | 1961 | 52.61888173034 | 1960 | 52.766244709331 |
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