Year | Value | 2022 | 78.7 | 2021 | 79.3 | 2020 | 79.2 | 2019 | 79.3 | 2018 | 79.1 | 2017 | 78.9 | 2016 | 78.6 | 2015 | 78.7 | 2014 | 78.4 | 2013 | 78 | 2012 | 77.7 | 2011 | 77.3 | 2010 | 76.7 | 2009 | 76.5 | 2008 | 76.3 | 2007 | 75.8 | 2006 | 75.8 | 2005 | 75.5 | 2004 | 75.3 | 2003 | 75.1 | 2002 | 74.9 | 2001 | 74.6 | 2000 | 74.1 | 1999 | 73.74 | 1998 | 73.52 | 1997 | 73.42 | 1996 | 73.03 | 1995 | 72.79 | 1994 | 72.82 | 1993 | 72.11 | 1992 | 71.67 | 1991 | 71.33 | 1990 | 70.94 | 1989 | 70.88 | 1988 | 70.66 | 1987 | 70.67 | 1986 | 70.56 | 1985 | 70.14 | 1984 | 70.48 | 1983 | 70.24 | 1982 | 70.22 | 1981 | 69.61 | 1980 | 69.24 | 1979 | 68.97 | 1978 | 68.58 | 1977 | 67.96 | 1976 | 67.53 | 1975 | 67.42 | 1974 | 66.93 |
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