Year | Value | 2021 | 1.981 | 2020 | 2.003 | 2019 | 2.031 | 2018 | 2.04 | 2017 | 2.043 | 2016 | 2.097 | 2015 | 2.114 | 2014 | 2.152 | 2013 | 2.184 | 2012 | 2.209 | 2011 | 2.262 | 2010 | 2.34 | 2009 | 2.44 | 2008 | 2.535 | 2007 | 2.626 | 2006 | 2.712 | 2005 | 2.808 | 2004 | 2.914 | 2003 | 3.002 | 2002 | 3.084 | 2001 | 3.146 | 2000 | 3.218 | 1999 | 3.304 | 1998 | 3.393 | 1997 | 3.491 | 1996 | 3.504 | 1995 | 3.605 | 1994 | 3.774 | 1993 | 3.852 | 1992 | 4.026 | 1991 | 4.24 | 1990 | 4.479 | 1989 | 4.676 | 1988 | 4.844 | 1987 | 5.073 | 1986 | 5.3 | 1985 | 5.541 | 1984 | 5.727 | 1983 | 5.891 | 1982 | 6.116 | 1981 | 6.239 | 1980 | 6.323 | 1979 | 6.424 | 1978 | 6.516 | 1977 | 6.593 | 1976 | 6.674 | 1975 | 6.737 | 1974 | 6.794 | 1973 | 6.819 | 1972 | 6.845 | 1971 | 6.865 | 1970 | 6.882 | 1969 | 6.863 | 1968 | 6.85 | 1967 | 6.854 | 1966 | 6.824 | 1965 | 6.83 | 1964 | 6.837 | 1963 | 6.841 | 1962 | 6.865 | 1961 | 6.831 | 1960 | 6.784 |
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