Year | Value | 2022 | 79.3 | 2021 | 76.6 | 2020 | 78.3 | 2019 | 79.5 | 2018 | 79.2 | 2017 | 79 | 2016 | 79 | 2015 | 78.6 | 2014 | 78.7 | 2013 | 78.7 | 2012 | 78.1 | 2011 | 78.2 | 2010 | 77.3 | 2009 | 77.1 | 2008 | 76.1 | 2007 | 76.1 | 2006 | 75.8 | 2005 | 75.6 | 2004 | 75.3 | 2003 | 75.1 | 2002 | 74.8 | 2001 | 74.9 | 2000 | 74.8 | 1999 | 74.2 | 1998 | 73.7 | 1997 | 73 | 1996 | 73.1 | 1995 | 73.4 | 1994 | 73.3 | 1993 | 73.2 | 1992 | 73.17 | 1991 | 73.17 | 1990 | 73.05 | 1989 | 72.65 | 1988 | 72.41 | 1987 | 72.3 | 1986 | 72.59 | 1985 | 72.78 | 1984 | 72.65 | 1983 | 72.61 | 1982 | 72.4 | 1981 | 72.17 | 1980 | 71.78 | 1979 | 71.75 | 1978 | 71.98 | 1977 | 72.18 | 1976 | 72.06 | 1975 | 71.97 | 1974 | 71.82 |
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