Year | Value | 2023 | 67.154 | 2022 | 66.724 | 2021 | 66.28 | 2020 | 66.09 | 2019 | 66.455 | 2018 | 66.332 | 2017 | 66.234 | 2016 | 66.167 | 2015 | 66.11 | 2014 | 66.042 | 2013 | 65.937 | 2012 | 65.771 | 2011 | 65.525 | 2010 | 65.213 | 2009 | 64.826 | 2008 | 64.384 | 2007 | 63.901 | 2006 | 63.349 | 2005 | 62.892 | 2004 | 62.439 | 2003 | 62.017 | 2002 | 61.607 | 2001 | 61.326 | 2000 | 61.008 | 1999 | 60.679 | 1998 | 60.339 | 1997 | 59.983 | 1996 | 59.59 | 1995 | 59.272 | 1994 | 58.986 | 1993 | 58.72 | 1992 | 58.549 | 1991 | 58.346 | 1990 | 58.206 | 1989 | 58.067 | 1988 | 57.974 | 1987 | 57.896 | 1986 | 57.848 | 1985 | 57.81 | 1984 | 57.734 | 1983 | 57.57 | 1982 | 57.485 | 1981 | 57.337 | 1980 | 57.135 | 1979 | 56.915 | 1978 | 56.65 | 1977 | 56.325 | 1976 | 55.959 | 1975 | 55.553 |
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