| Year | Value | | 2021 | 2.6223713685656 | | 2020 | 0.20446012502376 | | 2019 | 7.64702041887 | | 2018 | 8.9287793153105 | | 2017 | 5.1756543665867 | | 2016 | 42.184088435644 | | 2015 | 13.45569466592 | | 2014 | 9.5991637830382 | | 2013 | 14.887704962815 | | 2012 | -5.4514361826142 | | 2011 | 5.3071377294421 | | 2010 | 5.072771819611 | | 2009 | 11.676876342899 | | 2008 | 6.6416268240571 | | 2007 | -27.965153664431 | | 2006 | 5.2010139242762 | | 2005 | -6.7044098686657 | | 2004 | 0.69895917061922 | | 2003 | 3.1272530757217 | | 2002 | 6.1302326488224 | | 2001 | 0.050220098243486 | | 2000 | -3.5374635027339 | | 1999 | 6.1380532122419 | | 1998 | 10.627645352079 | | 1997 | 1.933859518222 | | 1996 | 23.436328433942 | | 1995 | 9.6391973762323 | | 1994 | 9.06789243941 | | 1993 | -27.255582602906 | | 1992 | 0.36038813186738 | | 1991 | -1.4667140756865 | | 1990 | 1.8296209901811 | | 1989 | 3.3439922355174 | | 1988 | 12.930675986563 | | 1987 | 0.69427924138158 | | 1986 | 1.6315190079943 | | 1985 | 11.673438674889 | | 1984 | 12.555915555207 | | 1983 | -2.718095187388 | | 1982 | -5.6668057922898 | | 1981 | -2.610828719277 | | 1980 | 5.5000530979781 | | 1979 | -7.3097313393634 | | 1978 | 7.3949898358127 | | 1977 | -3.5483272236431 | | 1976 | 38.723552363359 | | 1975 | -41.184920298963 | | 1974 | 66.216237069868 | | 1973 | 2.607842748364 | | 1972 | 1.4253366689262 |
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