Year | Value | 2021 | 22.318242 | 2020 | 13.421754 | 2019 | 13.708525 | 2018 | 17.76123 | 2017 | 47.76014 | 2016 | 26.00341450403 | 2015 | 20.919645107114 | 2014 | 17.313204 | 2013 | 16.930008 | 2012 | 17.175734601839 | 2011 | 18.42691392824 | 2009 | 26.785 | 2008 | 31.692 | 2007 | 30.617 | 2006 | 30.15 | 2005 | 30.879 | 2004 | 31.942 | 2003 | 40.577 | 2002 | 40.22 | 2001 | 54.26 | 2000 | 49.294 | 1999 | 62.7000007629 | 1998 | 73.1999969482 | 1997 | 56.2000007629 | 1996 | 44.4000015259 | 1995 | 33.2000007629 | 1994 | 29.7999992371 | 1993 | 23.7999992371 | 1992 | 22.2000007629 | 1991 | 18 | 1990 | 19 | 1989 | 22 | 1988 | 27.7999992371 | 1987 | 25.5 | 1986 | 22 | 1985 | 17.1000003815 | 1984 | 15.5 | 1983 | 15.8000001907 | 1982 | 12.6999998093 | 1981 | 12.3000001907 | 1980 | 10.3999996185 | 1979 | 11.6000003815 | 1978 | 10.3999996185 | 1977 | 9.3999996185 | 1976 | 12.3999996185 | 1975 | 13.6000003815 | 1974 | 10.3000001907 | 1973 | 12.3999996185 | 1972 | 10.3999996185 | 1971 | 9.1000003815 | 1970 | 9.1000003815 |
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