Year | Value | 2021 | 7.634130598203 | 2020 | 7.2017706354772 | 2019 | 7.0483746011056 | 2018 | 7.0301886700868 | 2017 | 7.0259229687758 | 2016 | 7.0013758542381 | 2015 | 7.0101687099825 | 2014 | 7.0347459674793 | 2013 | 7.0442675883556 | 2012 | 7.0467449164589 | 2011 | 7.0450012914256 | 2010 | 7.0231794566945 | 2009 | 6.993673611253 | 2008 | 7.0543641733229 | 2007 | 6.8773064765842 | 2006 | 6.79690348847 | 2005 | 6.5995981219781 | 2004 | 6.6258908975794 | 2003 | 6.5154530036059 | 2002 | 6.5299753603802 | 2001 | 6.5591576039934 | 2000 | 6.5876622294562 | 1999 | 6.5960743916945 | 1998 | 6.6253357571949 | 1997 | 6.6473525168903 | 1996 | 6.7123870251864 | 1995 | 6.736884135048 | 1994 | 6.704419709894 | 1993 | 6.8293082847201 | 1992 | 6.8719775461176 | 1991 | 6.9588192018551 | 1990 | 6.9737286371612 | 1989 | 6.9175357683289 | 1988 | 7.0484937953643 | 1987 | 7.13229259637 | 1986 | 7.2835750849898 | 1985 | 7.2784282051056 | 1984 | 7.370000539018 | 1983 | 7.4761115916175 | 1982 | 7.3013224517704 | 1981 | 7.1818485480745 | 1980 | 7.205628476391 | 1979 | 7.175371856045 | 1978 | 7.2733060155024 | 1977 | 7.814271759483 | 1976 | 8.4319155749863 | 1975 | 8.5949151125038 | 1974 | 8.4407251017254 | 1973 | 8.2631534896726 | 1972 | 8.8266531374493 | 1971 | 8.6019854170054 | 1970 | 8.902430282496 | 1969 | 9.2641077228691 | 1968 | 9.5248935639812 | 1967 | 9.681845162996 | 1966 | 10.201905594859 | 1965 | 11.183408141573 | 1964 | 12.22255728834 | 1963 | 11.253889898912 | 1962 | 11.291258884121 | 1961 | 14.51547903374 | 1960 | 23.064684622576 |
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