Year | Value | 2022 | 1.2032371305785 | 2021 | 1.154408018695 | 2020 | 1.1790073203829 | 2019 | 1.1307281685395 | 2018 | 1.1264876887821 | 2017 | 1.4585170388757 | 2016 | 1.3266200636314 | 2015 | 1.3275069929247 | 2014 | 1.1926213774454 | 2013 | 1.1817639634396 | 2012 | 1.1080741333163 | 2011 | 1.2496723681189 | 2010 | 1.3123221836286 | 2009 | 1.8865864200984 | 2008 | 1.8488990325372 | 2007 | 1.7875901053946 | 2006 | 1.6069783531837 | 2005 | 1.5302814886434 | 2004 | 1.8875329993028 | 2003 | 1.551720128915 | 2002 | 1.8216324922797 | 2001 | 1.932162071753 | 2000 | 2.043598472253 | 1999 | 2.3821114826797 | 1998 | 2.1450394048053 | 1997 | 1.4712040509333 | 1996 | 1.4505861516215 | 1995 | 1.5559849402365 | 1994 | 1.9142740052068 | 1993 | 2.3000590398457 | 1992 | 2.1022890833449 | 1991 | 3.1140828350649 | 1990 | 3.2974309433007 | 1989 | 2.9712458111333 | 1988 | 2.8973757314094 | 1987 | 2.6845067835936 | 1986 | 2.8609216797906 | 1985 | 2.6332768698802 | 1984 | 2.8198953941601 | 1983 | 2.6472502449755 | 1982 | 2.7044890585174 | 1981 | 2.6283957950267 | 1980 | 2.0718162122046 | 1979 | 2.0825544064836 | 1978 | 1.882087863914 | 1977 | 1.9979258847609 | 1976 | 2.141029900629 | 1975 | 2.0078427718862 | 1974 | 1.9719305512954 | 1973 | 1.9596116638169 | 1972 | 2.2292144786214 | 1970 | 2.1404465938745 |
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