Year | Value | 2021 | 1.483 | 2020 | 1.474 | 2019 | 1.382 | 2018 | 1.448 | 2017 | 1.541 | 2016 | 1.733 | 2015 | 1.724 | 2014 | 1.696 | 2013 | 1.668 | 2012 | 1.62 | 2011 | 1.515 | 2010 | 1.494 | 2009 | 1.509 | 2008 | 1.488 | 2007 | 1.429 | 2006 | 1.335 | 2005 | 1.252 | 2004 | 1.233 | 2003 | 1.232 | 2002 | 1.24 | 2001 | 1.286 | 2000 | 1.317 | 1999 | 1.31 | 1998 | 1.3 | 1997 | 1.25 | 1996 | 1.335 | 1995 | 1.406 | 1994 | 1.533 | 1993 | 1.623 | 1992 | 1.764 | 1991 | 1.805 | 1990 | 1.913 | 1989 | 2.026 | 1988 | 2.031 | 1987 | 2.03 | 1986 | 2.09 | 1985 | 2.09 | 1984 | 2.11 | 1983 | 2.11 | 1982 | 2.05 | 1981 | 2.02 | 1980 | 2.03 | 1979 | 2.05 | 1978 | 2.06 | 1977 | 2.08 | 1976 | 2.12 | 1975 | 2.17 | 1974 | 2.21 | 1973 | 2.25 | 1972 | 2.28 | 1971 | 2.31 | 1970 | 2.31 | 1969 | 2.26 | 1968 | 2.22 | 1967 | 2.26 | 1966 | 2.29 | 1965 | 2.27 | 1964 | 2.31 | 1963 | 2.4 | 1962 | 2.5 | 1961 | 2.59 | 1960 | 2.67 |
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