Year | Value | 2023 | 72.856 | 2022 | 72.692 | 2021 | 71.01 | 2020 | 69.775 | 2019 | 72.127 | 2018 | 71.342 | 2017 | 71.198 | 2016 | 70.76 | 2015 | 70.444 | 2014 | 70.101 | 2013 | 69.739 | 2012 | 69.549 | 2011 | 69.1 | 2010 | 68.712 | 2009 | 68.162 | 2008 | 67.933 | 2007 | 67.546 | 2006 | 67.425 | 2005 | 66.98 | 2004 | 66.61 | 2003 | 66.002 | 2002 | 65.362 | 2001 | 64.467 | 2000 | 63.728 | 1999 | 62.919 | 1998 | 62.165 | 1997 | 61.503 | 1996 | 60.988 | 1995 | 59.365 | 1994 | 60.288 | 1993 | 60.22 | 1992 | 60.156 | 1991 | 60.126 | 1990 | 60.1 | 1989 | 59.936 | 1988 | 59.75 | 1987 | 59.556 | 1986 | 59.367 | 1985 | 59.199 | 1984 | 58.933 | 1983 | 58.951 | 1982 | 58.837 | 1981 | 58.741 | 1980 | 58.616 | 1979 | 58.465 | 1978 | 58.269 | 1977 | 58.023 | 1976 | 57.615 | 1975 | 57.37 |
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