Year | Value | 2021 | 22.179114128678 | 2020 | 22.179114128678 | 2019 | 22.170606165381 | 2018 | 22.171214276477 | 2017 | 21.330360460795 | 2016 | 21.165559917923 | 2015 | 21.003990758244 | 2014 | 20.730346037315 | 2013 | 20.730346037315 | 2012 | 20.730346037315 | 2011 | 20.730346037315 | 2010 | 19.135704034444 | 2009 | 19.135704034444 | 2008 | 19.135704034444 | 2007 | 15.946420028704 | 2006 | 16.743741030139 | 2005 | 17.541062031574 | 2004 | 14.351778025833 | 2003 | 15.149099027268 | 2002 | 14.925849146867 | 2001 | 14.606920746293 | 2000 | 14.590974326264 | 1999 | 14.431510125977 | 1998 | 14.176367405517 | 1997 | 14.160420985489 | 1996 | 14.14447456546 | 1995 | 14.128528145431 | 1994 | 14.080688885345 | 1993 | 14.032849625259 | 1992 | 14.431510125977 | 1991 | 14.399617285919 | 1990 | 14.351778025833 | 1989 | 14.367724445862 | 1988 | 14.319885185776 | 1987 | 14.27204592569 | 1986 | 14.14447456546 | 1985 | 13.969063945144 | 1984 | 13.905278265029 | 1983 | 13.857439004943 | 1982 | 13.666081964599 | 1981 | 14.351778025833 | 1980 | 14.351778025833 | 1979 | 14.351778025833 | 1978 | 15.946420028704 | 1977 | 15.149099027268 | 1976 | 14.351778025833 | 1975 | 13.554457024398 | 1974 | 13.299314303939 | 1973 | 13.203635783767 | 1972 | 13.107957263594 | 1971 | 13.012278743422 | 1970 | 12.91660022325 | 1969 | 12.820921703078 | 1968 | 12.725243182905 | 1967 | 12.629564662733 | 1966 | 12.629564662733 | 1965 | 12.645511082762 | 1964 | 12.597671822676 | 1963 | 12.629564662733 | 1962 | 9.2010843565619 | 1961 | 9.4881199170786 |
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