Year | Value | 2022 | 49.22842741948 | 2021 | 49.226415746163 | 2020 | 49.205959365443 | 2019 | 49.171261676473 | 2018 | 49.122724461337 | 2017 | 49.07005090367 | 2016 | 49.011084790344 | 2015 | 48.943229964101 | 2014 | 48.871374053924 | 2013 | 48.807745775535 | 2012 | 48.784037770788 | 2011 | 48.786767907816 | 2010 | 48.785622373453 | 2009 | 48.786383856618 | 2008 | 48.786045110402 | 2007 | 48.782472312018 | 2006 | 48.785437272645 | 2005 | 48.796948535976 | 2004 | 48.806138754387 | 2003 | 48.810841547442 | 2002 | 48.79895007872 | 2001 | 48.784581013471 | 2000 | 48.779690621747 | 1999 | 48.769158977071 | 1998 | 48.746591482649 | 1997 | 48.708738785122 | 1996 | 48.649338199901 | 1995 | 48.593837612688 | 1994 | 48.660059059147 | 1993 | 48.931658559856 | 1992 | 49.330102695914 | 1991 | 49.537689571707 | 1990 | 49.560243952909 | 1989 | 49.573309113792 | 1988 | 49.578094333366 | 1987 | 49.576582663334 | 1986 | 49.571892162323 | 1985 | 49.561677875102 | 1984 | 49.544567002414 | 1983 | 49.527364620369 | 1982 | 49.503733376571 | 1981 | 49.466993392305 | 1980 | 49.418522698592 | 1979 | 49.359106241707 | 1978 | 49.289619972886 | 1977 | 49.213819743411 | 1976 | 49.133518175564 | 1975 | 49.049722905256 | 1974 | 48.963599119572 | 1973 | 48.877141941269 | 1972 | 48.794367864845 | 1971 | 48.718349354614 | 1970 | 48.650617825269 | 1969 | 48.590485405169 | 1968 | 48.537240936035 | 1967 | 48.49077154556 | 1966 | 48.450570570604 | 1965 | 48.418335966425 | 1964 | 48.392840395227 | 1963 | 48.370814015935 | 1962 | 48.350470788 | 1961 | 48.331069399666 | 1960 | 48.312250060459 |
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