Year | Value | 2022 | 49.571243323037 | 2021 | 49.598457396178 | 2020 | 49.613691419063 | 2019 | 49.641163873351 | 2018 | 49.677785162062 | 2017 | 49.706694249731 | 2016 | 49.729078342534 | 2015 | 49.759743394792 | 2014 | 49.803104038009 | 2013 | 49.851931250935 | 2012 | 49.90350327192 | 2011 | 49.953519051417 | 2010 | 50.012165483816 | 2009 | 50.0923958472 | 2008 | 50.224288298639 | 2007 | 50.368795612064 | 2006 | 50.501397575081 | 2005 | 50.62562401273 | 2004 | 50.718691891637 | 2003 | 50.803454389196 | 2002 | 50.883224643515 | 2001 | 50.947741636615 | 2000 | 50.995946563092 | 1999 | 51.032514549505 | 1998 | 51.067825870961 | 1997 | 51.105994395605 | 1996 | 51.135908889445 | 1995 | 51.161631059305 | 1994 | 51.185730910735 | 1993 | 51.202826178037 | 1992 | 51.220146807328 | 1991 | 51.228215115694 | 1990 | 51.220274534997 | 1989 | 51.209869910744 | 1988 | 51.208595388361 | 1987 | 51.214577461122 | 1986 | 51.220719127144 | 1985 | 51.228171702613 | 1984 | 51.234049169951 | 1983 | 51.232035928242 | 1982 | 51.227319604998 | 1981 | 51.229051146937 | 1980 | 51.244173029676 | 1979 | 51.27299235457 | 1978 | 51.309428922645 | 1977 | 51.348849291715 | 1976 | 51.396349676513 | 1975 | 51.448758369188 | 1974 | 51.465678742063 | 1973 | 51.449997384209 | 1972 | 51.434716328627 | 1971 | 51.631168352078 | 1970 | 51.817290788261 | 1969 | 51.799607778765 | 1968 | 51.804713232705 | 1967 | 51.812630674936 | 1966 | 51.820877431225 | 1965 | 51.826329224165 | 1964 | 51.833474784835 | 1963 | 51.842863797703 | 1962 | 51.856536967679 | 1961 | 51.878266173496 | 1960 | 51.902522696598 |
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