Year | Value | 2022 | 74.491281653832 | 2021 | 72.504240745174 | 2020 | 73.775170228739 | 2019 | 74.362878288079 | 2018 | 74.919552362478 | 2017 | 74.504600717987 | 2016 | 74.553582742772 | 2015 | 74.954031831907 | 2014 | 76.045010053268 | 2013 | 76.773951333741 | 2012 | 76.24712338742 | 2011 | 75.592058681621 | 2010 | 75.170767425575 | 2009 | 75.564748517055 | 2008 | 73.390437509648 | 2007 | 71.261563319131 | 2006 | 71.986966075814 | 2005 | 72.282329627116 | 2004 | 72.438790282451 | 2003 | 73.677828109653 | 2002 | 73.675152119314 | 2001 | 73.719096494636 | 2000 | 73.352383448711 | 1999 | 73.35485969074 | 1998 | 74.011773515865 | 1997 | 73.815436308994 | 1996 | 75.197247057802 | 1995 | 74.359052321474 | 1994 | 74.417230646776 | 1993 | 74.95552595889 | 1992 | 75.103959082044 | 1991 | 75.651858669379 | 1990 | 74.412494601604 | 1989 | 74.667251887911 | 1988 | 75.944619103364 | 1987 | 78.608112344308 | 1986 | 79.102100120455 | 1985 | 80.106966028783 | 1984 | 79.84624273013 | 1983 | 81.020169371221 | 1982 | 80.835410981452 | 1981 | 80.366165526768 | 1980 | 77.57058653403 | 1979 | 77.126661295832 | 1978 | 75.655612364601 | 1977 | 75.12451351337 | 1976 | 73.712403490855 | 1975 | 73.73048443435 | 1974 | 70.261625704133 | 1973 | 70.516904367415 | 1972 | 69.847535897016 | 1971 | 69.376588724414 | 1970 | 67.969611202595 |
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