| Year | Value | | 2021 | 0.77994428969359 | | 2020 | 0.77994428969359 | | 2019 | 0.78212290502793 | | 2018 | 0.7843137254902 | | 2017 | 0.78651685393258 | | 2016 | 0.78984485190409 | | 2015 | 0.78984485190409 | | 2014 | 0.78984485190409 | | 2013 | 0.80622347949081 | | 2012 | 0.89235127478753 | | 2011 | 0.89488636363636 | | 2010 | 0.91168091168091 | | 2009 | 0.85714285714286 | | 2008 | 0.85714285714286 | | 2007 | 1.0071942446043 | | 2006 | 0.93659942363112 | | 2005 | 0.95791001451379 | | 2004 | 1.0159651669086 | | 2003 | 0.87336244541485 | | 2002 | 1.4814814814815 | | 2001 | 1.4925373134328 | | 2000 | 1.4925373134328 | | 1999 | 1.4925373134328 | | 1998 | 1.4925373134328 | | 1997 | 1.4925373134328 | | 1996 | 1.4925373134328 | | 1995 | 1.4925373134328 | | 1994 | 1.4925373134328 | | 1993 | 1.4925373134328 | | 1992 | 1.4925373134328 | | 1991 | 1.4925373134328 | | 1990 | 1.4925373134328 | | 1989 | 1.4925373134328 | | 1988 | 2.9850746268657 | | 1987 | 2.9850746268657 | | 1986 | 2.9850746268657 | | 1985 | 2.9850746268657 | | 1984 | 2.9850746268657 | | 1983 | 2.9850746268657 | | 1982 | 2.9850746268657 | | 1981 | 2.9850746268657 | | 1980 | 2.9850746268657 | | 1979 | 2.9850746268657 | | 1978 | 2.9850746268657 | | 1977 | 2.9850746268657 | | 1976 | 2.9850746268657 | | 1975 | 2.9850746268657 | | 1974 | 2.9850746268657 | | 1973 | 4.4776119402985 | | 1972 | 4.4776119402985 | | 1971 | 2.9850746268657 | | 1970 | 5.9701492537313 | | 1969 | 4.4776119402985 | | 1968 | 4.4776119402985 | | 1967 | 5.9701492537313 | | 1966 | 5.9701492537313 | | 1965 | 5.9701492537313 | | 1964 | 5.9701492537313 | | 1963 | 5.9701492537313 | | 1962 | 5.9701492537313 | | 1961 | 4.4776119402985 |
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