Year | Value | 2022 | 57.99 | 2021 | 57.821 | 2020 | 57.671 | 2019 | 57.54 | 2018 | 57.428 | 2017 | 57.336 | 2016 | 57.264 | 2015 | 57.191 | 2014 | 57.118 | 2013 | 57.046 | 2012 | 56.973 | 2011 | 56.9 | 2010 | 56.827 | 2009 | 56.755 | 2008 | 56.682 | 2007 | 56.609 | 2006 | 56.536 | 2005 | 56.463 | 2004 | 56.39 | 2003 | 56.317 | 2002 | 56.244 | 2001 | 56.171 | 2000 | 56.098 | 1999 | 56.025 | 1998 | 55.986 | 1997 | 55.964 | 1996 | 55.943 | 1995 | 55.921 | 1994 | 55.9 | 1993 | 55.992 | 1992 | 56.083 | 1991 | 56.175 | 1990 | 56.266 | 1989 | 56.357 | 1988 | 56.341 | 1987 | 56.231 | 1986 | 56.121 | 1985 | 56.01 | 1984 | 55.9 | 1983 | 55.461 | 1982 | 55.022 | 1981 | 54.582 | 1980 | 54.142 | 1979 | 53.7 | 1978 | 53.356 | 1977 | 53.092 | 1976 | 52.828 | 1975 | 52.564 | 1974 | 52.3 | 1973 | 51.785 | 1972 | 51.269 | 1971 | 50.753 | 1970 | 50.236 | 1969 | 49.647 | 1968 | 48.997 | 1967 | 48.346 | 1966 | 47.696 | 1965 | 47.047 | 1964 | 46.4 | 1963 | 45.847 | 1962 | 45.296 | 1961 | 44.746 | 1960 | 44.198 |
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