| Year | Value | | 2022 | -1.5696583413986 | | 2021 | -1.6777912474095 | | 2020 | -1.596766194768 | | 2019 | -1.196439517518 | | 2018 | 0.52517874401174 | | 2017 | 0.31953603831286 | | 2016 | 1.0603164405684 | | 2015 | 1.3195939025152 | | 2014 | 1.3476413956365 | | 2013 | 1.133678906543 | | 2012 | 0.82992959503699 | | 2011 | 1.4208976627667 | | 2010 | 1.26551415533 | | 2009 | 0.65115206175087 | | 2008 | 1.2582253073275 | | 2007 | 1.974862197935 | | 2006 | 2.5681142571775 | | 2005 | 2.5500738074024 | | 2004 | 1.7250295280859 | | 2003 | 2.0621024671107 | | 2002 | 0.1223611199243 | | 2001 | -3.6617798581649 | | 2000 | -4.0753861316229 | | 1999 | -3.5537378161317 | | 1998 | -1.7047505095712 | | 1997 | 0.44329034406703 | | 1996 | 0.80084148782361 | | 1995 | 0.35131468412075 | | 1994 | 0.2291221336758 | | 1993 | 0.26855340884975 | | 1992 | 0.34060002057992 | | 1991 | 0.68805632332348 | | 1990 | -1.0515358387764 | | 1989 | -1.5645629096414 | | 1988 | -1.4645601140241 | | 1987 | 0.79311735694472 | | 1986 | 0.032091901000121 | | 1985 | 0.50615402282103 | | 1984 | 0.51534431224178 | | 1983 | 0.70238621102508 | | 1982 | 0.98551328210375 | | 1981 | 0.39640055951291 | | 1980 | 0.12842525388588 | | 1979 | 0.33086676683633 | | 1978 | 0.7508430170637 | | 1977 | 0.040152849049462 | | 1976 | 0.18088760425872 | | 1975 | 0.52306156635498 | | 1974 | 0.97473194629387 | | 1973 | 0.54171239856969 | | 1972 | 0.21755419476669 | | 1971 | 1.8143229630895 | | 1970 | 1.5021861202663 | | 1969 | 1.6141527431972 | | 1968 | 1.5501068178485 | | 1967 | 1.0610603802034 | | 1966 | 1.0413849683558 | | 1965 | 1.5781918681503 | | 1964 | 1.7333242052139 | | 1963 | 1.8868629861623 | | 1962 | 1.7985940906197 | | 1961 | 1.0352711103488 |
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