Year | Value | 2022 | 49.764452528401 | 2021 | 49.770028906131 | 2020 | 49.774240044854 | 2019 | 49.793548811231 | 2018 | 49.827453617291 | 2017 | 49.862012645996 | 2016 | 49.881672187738 | 2015 | 49.887019731148 | 2014 | 49.897706727567 | 2013 | 49.913996851556 | 2012 | 49.935651439699 | 2011 | 49.962765139813 | 2010 | 49.995274563126 | 2009 | 50.03369686518 | 2008 | 50.077684401163 | 2007 | 50.127330405788 | 2006 | 50.180928723344 | 2005 | 50.239672809917 | 2004 | 50.30645921735 | 2003 | 50.336063704769 | 2002 | 50.331188612049 | 2001 | 50.32725320909 | 2000 | 50.306469582195 | 1999 | 50.268500103525 | 1998 | 50.23461166488 | 1997 | 50.212560367342 | 1996 | 50.193004887839 | 1995 | 50.176120390276 | 1994 | 50.15966950946 | 1993 | 50.145040771133 | 1992 | 50.132011744189 | 1991 | 50.103215857935 | 1990 | 50.063207606253 | 1989 | 50.03336638194 | 1988 | 50.006371455878 | 1987 | 49.976693618083 | 1986 | 49.938870872489 | 1985 | 49.891920670837 | 1984 | 49.835367988098 | 1983 | 49.768768760337 | 1982 | 49.693850795124 | 1981 | 49.62099021853 | 1980 | 49.583343485782 | 1979 | 49.592767577321 | 1978 | 49.626548201261 | 1977 | 49.663929807615 | 1976 | 49.697725148021 | 1975 | 49.730391806768 | 1974 | 49.759862210593 | 1973 | 49.781593156586 | 1972 | 49.796437758356 | 1971 | 49.804870998049 | 1970 | 49.813287339437 | 1969 | 49.823306582148 | 1968 | 49.836283705337 | 1967 | 49.847317014457 | 1966 | 49.867118872767 | 1965 | 49.905321975072 | 1964 | 49.947547053379 | 1963 | 49.989348619678 | 1962 | 50.033328889481 | 1961 | 50.080305311227 | 1960 | 50.130868556648 |
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