Year | Value | 2022 | 50.387092050073 | 2021 | 50.345830788108 | 2020 | 50.296716185142 | 2019 | 50.26567380924 | 2018 | 50.238006879089 | 2017 | 50.20869490813 | 2016 | 50.181184784498 | 2015 | 50.158070260621 | 2014 | 50.138536568836 | 2013 | 50.120508808886 | 2012 | 50.102437907243 | 2011 | 50.085965565981 | 2010 | 50.071126690892 | 2009 | 50.055201611956 | 2008 | 50.038207407918 | 2007 | 50.020359565273 | 2006 | 50.001518565125 | 2005 | 49.981682561639 | 2004 | 49.96133731553 | 2003 | 49.940946764403 | 2002 | 49.907945809737 | 2001 | 49.857336216743 | 2000 | 49.802386880862 | 1999 | 49.748168353403 | 1998 | 49.694736824933 | 1997 | 49.642961998354 | 1996 | 49.593310463137 | 1995 | 49.544807797924 | 1994 | 49.496064509474 | 1993 | 49.462629326957 | 1992 | 49.44507234405 | 1991 | 49.428224053213 | 1990 | 49.412779908683 | 1989 | 49.398267552386 | 1988 | 49.383349353451 | 1987 | 49.366277037371 | 1986 | 49.345629125356 | 1985 | 49.321620834435 | 1984 | 49.294916049702 | 1983 | 49.265843738617 | 1982 | 49.234474068396 | 1981 | 49.200441485862 | 1980 | 49.18247909825 | 1979 | 49.181965584456 | 1978 | 49.181715163824 | 1977 | 49.182397271618 | 1976 | 49.183864948793 | 1975 | 49.185610509648 | 1974 | 49.18724480392 | 1973 | 49.188947984518 | 1972 | 49.190487942958 | 1971 | 49.191393163684 | 1970 | 49.177880580443 | 1969 | 49.14873771105 | 1968 | 49.117257598167 | 1967 | 49.083823761805 | 1966 | 49.048715440833 | 1965 | 49.012172192377 | 1964 | 48.97444865954 | 1963 | 48.936940821721 | 1962 | 48.898672016361 | 1961 | 48.857723335038 | 1960 | 48.816047565875 |
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