Year | Value | 2022 | 49.702414265896 | 2021 | 49.689464381052 | 2020 | 49.682512724585 | 2019 | 49.669595494211 | 2018 | 49.650469436555 | 2017 | 49.628481057753 | 2016 | 49.605655754721 | 2015 | 49.583703687794 | 2014 | 49.563223155534 | 2013 | 49.545233893263 | 2012 | 49.528548761628 | 2011 | 49.512438185089 | 2010 | 49.500524068044 | 2009 | 49.494654397187 | 2008 | 49.489112599228 | 2007 | 49.486505956355 | 2006 | 49.486548092309 | 2005 | 49.485934271485 | 2004 | 49.486482339659 | 2003 | 49.485021899443 | 2002 | 49.479729763394 | 2001 | 49.472344383266 | 2000 | 49.464942589644 | 1999 | 49.455654888443 | 1998 | 49.44649082715 | 1997 | 49.438336317463 | 1996 | 49.430875954461 | 1995 | 49.425105789805 | 1994 | 49.418631695488 | 1993 | 49.414002386453 | 1992 | 49.412346702476 | 1991 | 49.412491233891 | 1990 | 49.415425612069 | 1989 | 49.422544102867 | 1988 | 49.434296158639 | 1987 | 49.449016411997 | 1986 | 49.466888232069 | 1985 | 49.488016564681 | 1984 | 49.511245971538 | 1983 | 49.537333798109 | 1982 | 49.565842291974 | 1981 | 49.595000969944 | 1980 | 49.625590580074 | 1979 | 49.656684368347 | 1978 | 49.688452728603 | 1977 | 49.720098045796 | 1976 | 49.751470046174 | 1975 | 49.78359508866 | 1974 | 49.81168880395 | 1973 | 49.835784457712 | 1972 | 49.8587454864 | 1971 | 49.876625803309 | 1970 | 49.888806955467 | 1969 | 49.894742349907 | 1968 | 49.896552266013 | 1967 | 49.896004338725 | 1966 | 49.889516896041 | 1965 | 49.879156463319 | 1964 | 49.866671662061 | 1963 | 49.853830963384 | 1962 | 49.842664751296 | 1961 | 49.831124922912 | 1960 | 49.819052568594 |
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