Year | Value | 2022 | 48.939924820204 | 2021 | 48.987153632257 | 2020 | 48.999936454979 | 2019 | 49.008400207906 | 2018 | 49.020644729171 | 2017 | 49.039105787868 | 2016 | 49.061791436483 | 2015 | 49.094126472786 | 2014 | 49.138242040459 | 2013 | 49.190009075079 | 2012 | 49.251311266747 | 2011 | 49.320123855889 | 2010 | 49.389561132388 | 2009 | 49.461724738537 | 2008 | 49.53345440783 | 2007 | 49.598543676672 | 2006 | 49.657804954452 | 2005 | 49.710431901962 | 2004 | 49.753807683626 | 2003 | 49.785477450268 | 2002 | 49.807044795725 | 2001 | 49.819620017084 | 2000 | 49.824494394828 | 1999 | 49.819171825151 | 1998 | 49.80147584779 | 1997 | 49.774070039437 | 1996 | 49.743053512808 | 1995 | 49.706620859743 | 1994 | 49.65965451148 | 1993 | 49.605578333802 | 1992 | 49.549033687243 | 1991 | 49.493102422575 | 1990 | 49.43808903973 | 1989 | 49.385520671361 | 1988 | 49.336302052007 | 1987 | 49.286225011693 | 1986 | 49.233721449097 | 1985 | 49.178583924763 | 1984 | 49.122816743738 | 1983 | 49.065450383563 | 1982 | 49.00254648663 | 1981 | 48.937168873873 | 1980 | 48.872103462844 | 1979 | 48.808050050804 | 1978 | 48.747389454431 | 1977 | 48.692998825813 | 1976 | 48.647162993728 | 1975 | 48.608305230361 | 1974 | 48.573450568353 | 1973 | 48.549049835052 | 1972 | 48.537514563346 | 1971 | 48.532382226019 | 1970 | 48.535127438407 | 1969 | 48.547173409579 | 1968 | 48.566159911265 | 1967 | 48.590918573428 | 1966 | 48.624878676811 | 1965 | 48.66473600247 | 1964 | 48.70312329743 | 1963 | 48.742032116914 | 1962 | 48.780799936306 | 1961 | 48.817066009388 | 1960 | 48.8532343623 |
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