Year | Value | 2021 | 79.6 | 2020 | 80.9 | 2019 | 81.6 | 2018 | 81.4 | 2017 | 80.9 | 2016 | 81.3 | 2015 | 80.4 | 2014 | 80.5 | 2013 | 80.2 | 2012 | 80.1 | 2011 | 79.9 | 2010 | 79.6 | 2009 | 79.6 | 2008 | 79.6 | 2007 | 79.25 | 2006 | 79.33 | 2005 | 78.83 | 2004 | 79.08 | 2003 | 78.23 | 2002 | 78.4 | 2001 | 78.17 | 2000 | 76.68 | 1999 | 76.55 | 1998 | 76.22 | 1997 | 76.9 | 1996 | 76.76 | 1995 | 76.52 | 1994 | 76.28 | 1993 | 76.04 | 1992 | 75.8 | 1991 | 75.95 | 1990 | 75.93 | 1989 | 75.64 | 1988 | 75.34 | 1987 | 75.24 | 1986 | 75.24 | 1985 | 74.83 | 1984 | 74.27 | 1983 | 74.27 | 1982 | 74.36 | 1981 | 74.15 | 1980 | 74.15 | 1979 | 74.11 | 1978 | 74.16 | 1977 | 74.13 | 1976 | 73.8 | 1975 | 73.49 | 1974 | 74.085 | 1973 | 73.755 | 1972 | 73.399 | 1971 | 72.976 | 1970 | 72.692 | 1969 | 72.428 | 1968 | 71.918 | 1967 | 71.766 | 1966 | 71.253 | 1965 | 70.98 | 1964 | 70.345 | 1963 | 69.804 | 1962 | 69.466 | 1961 | 69.064 | 1960 | 68.323 |
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