Year | Value | 2021 | 15.340442986054 | 2020 | 15.340442986054 | 2019 | 15.340442986054 | 2018 | 15.340442986054 | 2017 | 15.340442986054 | 2016 | 15.340442986054 | 2015 | 15.340442986054 | 2014 | 15.340442986054 | 2013 | 15.340442986054 | 2012 | 15.340442986054 | 2011 | 15.340442986054 | 2010 | 15.340442986054 | 2009 | 15.340442986054 | 2008 | 15.340442986054 | 2007 | 15.340442986054 | 2006 | 15.176374077112 | 2005 | 15.012305168171 | 2004 | 14.848236259229 | 2003 | 14.766201804758 | 2002 | 14.602132895816 | 2001 | 14.520098441345 | 2000 | 14.356029532404 | 1999 | 14.191960623462 | 1998 | 14.109926168991 | 1997 | 13.781788351107 | 1996 | 13.699753896637 | 1995 | 13.535684987695 | 1994 | 13.12551271534 | 1993 | 13.04347826087 | 1992 | 12.879409351928 | 1991 | 12.633305988515 | 1990 | 12.469237079573 | 1989 | 12.223133716161 | 1988 | 12.059064807219 | 1987 | 11.730926989336 | 1986 | 11.566858080394 | 1985 | 11.23872026251 | 1984 | 11.074651353569 | 1983 | 11.074651353569 | 1982 | 10.828547990156 | 1981 | 10.746513535685 | 1980 | 10.500410172272 | 1979 | 10.500410172272 | 1978 | 10.418375717801 | 1977 | 10.418375717801 | 1976 | 10.336341263331 | 1975 | 10.336341263331 | 1974 | 9.8441345365053 | 1973 | 9.8441345365053 | 1972 | 9.8441345365053 | 1971 | 9.8441345365053 | 1970 | 9.8441345365053 | 1969 | 9.2698933552092 | 1968 | 9.2698933552092 | 1967 | 9.2698933552092 | 1966 | 9.2698933552092 | 1965 | 9.2698933552092 | 1964 | 8.6136177194422 | 1963 | 8.6136177194422 | 1962 | 8.6136177194422 | 1961 | 8.6136177194422 |
|