Year | Value | 2023 | 79.107 | 2022 | 79.048 | 2021 | 75.778 | 2020 | 78.254 | 2019 | 78.888 | 2018 | 78.75 | 2017 | 78.194 | 2016 | 77.886 | 2015 | 77.855 | 2014 | 77.592 | 2013 | 77.614 | 2012 | 77.322 | 2011 | 76.868 | 2010 | 76.386 | 2009 | 75.394 | 2008 | 75.961 | 2007 | 75.565 | 2006 | 75.639 | 2005 | 74.655 | 2004 | 74.767 | 2003 | 74.625 | 2002 | 73.908 | 2001 | 73.865 | 2000 | 73.9 | 1999 | 73.86 | 1998 | 73.612 | 1997 | 73.448 | 1996 | 74.871 | 1995 | 73.898 | 1994 | 73.112 | 1993 | 72.669 | 1992 | 72.32 | 1991 | 72.588 | 1990 | 72.819 | 1989 | 72.731 | 1988 | 72.723 | 1987 | 73.117 | 1986 | 73.057 | 1985 | 72.942 | 1984 | 72.745 | 1983 | 73.175 | 1982 | 73.095 | 1981 | 72.764 | 1980 | 72.232 | 1979 | 71.95 | 1978 | 71.619 | 1977 | 71.229 | 1976 | 70.89 | 1975 | 70.562 |
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