Year | Value | 2021 | 2.321 | 2020 | 2.349 | 2019 | 2.377 | 2018 | 2.404 | 2017 | 2.43 | 2016 | 2.455 | 2015 | 2.48 | 2014 | 2.503 | 2013 | 2.526 | 2012 | 2.55 | 2011 | 2.575 | 2010 | 2.601 | 2009 | 2.628 | 2008 | 2.657 | 2007 | 2.689 | 2006 | 2.725 | 2005 | 2.767 | 2004 | 2.816 | 2003 | 2.874 | 2002 | 2.941 | 2001 | 3.019 | 2000 | 3.111 | 1999 | 3.218 | 1998 | 3.339 | 1997 | 3.473 | 1996 | 3.62 | 1995 | 3.775 | 1994 | 3.937 | 1993 | 4.102 | 1992 | 4.267 | 1991 | 4.432 | 1990 | 4.596 | 1989 | 4.762 | 1988 | 4.931 | 1987 | 5.073 | 1986 | 5.217 | 1985 | 5.359 | 1984 | 5.488 | 1983 | 5.611 | 1982 | 5.737 | 1981 | 5.84 | 1980 | 5.959 | 1979 | 6.069 | 1978 | 6.186 | 1977 | 6.301 | 1976 | 6.407 | 1975 | 6.499 | 1974 | 6.576 | 1973 | 6.652 | 1972 | 6.708 | 1971 | 6.764 | 1970 | 6.811 | 1969 | 6.855 | 1968 | 6.907 | 1967 | 6.953 | 1966 | 6.988 | 1965 | 7.034 | 1964 | 7.069 | 1963 | 7.108 | 1962 | 7.128 | 1961 | 7.149 | 1960 | 7.159 |
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