Year | Value | 2022 | 49.609059518022 | 2021 | 49.611855233915 | 2020 | 49.611640589867 | 2019 | 49.607334877227 | 2018 | 49.601971491728 | 2017 | 49.594102734952 | 2016 | 49.586074596649 | 2015 | 49.578989277279 | 2014 | 49.571330993061 | 2013 | 49.562764214293 | 2012 | 49.552928841386 | 2011 | 49.542515702847 | 2010 | 49.532418101377 | 2009 | 49.523152491499 | 2008 | 49.512630770861 | 2007 | 49.499215633549 | 2006 | 49.485694387087 | 2005 | 49.472786564487 | 2004 | 49.459842705016 | 2003 | 49.450070508504 | 2002 | 49.445019345043 | 2001 | 49.440630214065 | 2000 | 49.436264371898 | 1999 | 49.45099054914 | 1998 | 49.484832115655 | 1997 | 49.507103600765 | 1996 | 49.52044494321 | 1995 | 49.529158425221 | 1994 | 49.516919029529 | 1993 | 49.49800969378 | 1992 | 49.483730457931 | 1991 | 49.463210084245 | 1990 | 49.438106927061 | 1989 | 49.40984280919 | 1988 | 49.378694290604 | 1987 | 49.341886089428 | 1986 | 49.300434746812 | 1985 | 49.258045059731 | 1984 | 49.213061697896 | 1983 | 49.167053810225 | 1982 | 49.121362997325 | 1981 | 49.074781456318 | 1980 | 49.025508031357 | 1979 | 48.973009053861 | 1978 | 48.916344769613 | 1977 | 48.862208440604 | 1976 | 48.811524794572 | 1975 | 48.758677665516 | 1974 | 48.705300574673 | 1973 | 48.650520414977 | 1972 | 48.592724372478 | 1971 | 48.532570345357 | 1970 | 48.470565782109 | 1969 | 48.405793090305 | 1968 | 48.336756331179 | 1967 | 48.265046133075 | 1966 | 48.190314672971 | 1965 | 48.12360228266 | 1964 | 48.069997061745 | 1963 | 48.01024579557 | 1962 | 47.940623709288 | 1961 | 47.870031577301 | 1960 | 47.791989530626 |
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