Year | Value | 2021 | 2.496 | 2020 | 2.541 | 2019 | 2.571 | 2018 | 2.619 | 2017 | 2.671 | 2016 | 2.722 | 2015 | 2.766 | 2014 | 2.802 | 2013 | 2.872 | 2012 | 2.953 | 2011 | 3.049 | 2010 | 3.145 | 2009 | 3.264 | 2008 | 3.375 | 2007 | 3.494 | 2006 | 3.597 | 2005 | 3.673 | 2004 | 3.808 | 2003 | 3.911 | 2002 | 4.037 | 2001 | 4.209 | 2000 | 4.4 | 1999 | 4.655 | 1998 | 4.776 | 1997 | 4.964 | 1996 | 5.148 | 1995 | 5.346 | 1994 | 5.548 | 1993 | 5.75 | 1992 | 5.882 | 1991 | 5.996 | 1990 | 6.084 | 1989 | 6.153 | 1988 | 6.21 | 1987 | 6.273 | 1986 | 6.321 | 1985 | 6.361 | 1984 | 6.381 | 1983 | 6.376 | 1982 | 6.369 | 1981 | 6.35 | 1980 | 6.332 | 1979 | 6.314 | 1978 | 6.298 | 1977 | 6.293 | 1976 | 6.289 | 1975 | 6.287 | 1974 | 6.289 | 1973 | 6.281 | 1972 | 6.284 | 1971 | 6.295 | 1970 | 6.31 | 1969 | 6.301 | 1968 | 6.298 | 1967 | 6.306 | 1966 | 6.307 | 1965 | 6.316 | 1964 | 6.313 | 1963 | 6.318 | 1962 | 6.313 | 1961 | 6.31 | 1960 | 6.292 |
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