Year | Value | 2021 | 67.737 | 2020 | 68.475 | 2019 | 68.268 | 2018 | 68.017 | 2017 | 67.745 | 2016 | 67.446 | 2015 | 67.137 | 2014 | 66.787 | 2013 | 66.44 | 2012 | 66.081 | 2011 | 65.697 | 2010 | 65.304 | 2009 | 64.854 | 2008 | 64.329 | 2007 | 63.723 | 2006 | 63.073 | 2005 | 62.328 | 2004 | 61.628 | 2003 | 60.871 | 2002 | 60.148 | 2001 | 59.362 | 2000 | 58.568 | 1999 | 45.701 | 1998 | 49.123 | 1997 | 49.517 | 1996 | 48.816 | 1995 | 48.024 | 1994 | 48.252 | 1993 | 47.254 | 1992 | 46.276 | 1991 | 44.985 | 1990 | 44.953 | 1989 | 44.55 | 1988 | 35.753 | 1987 | 35.644 | 1986 | 34.344 | 1985 | 33.795 | 1984 | 33.751 | 1983 | 31.635 | 1982 | 30.824 | 1981 | 29.567 | 1980 | 28.446 | 1979 | 22.529 | 1978 | 21.837 | 1977 | 24.427 | 1976 | 25.957 | 1975 | 24.834 | 1974 | 36.877 | 1973 | 38.994 | 1972 | 38.318 | 1971 | 37.722 | 1970 | 37.166 | 1969 | 36.712 | 1968 | 36.225 | 1967 | 35.73 | 1966 | 34.998 | 1965 | 34.357 | 1964 | 33.602 | 1963 | 33.258 | 1962 | 32.953 | 1961 | 32.574 | 1960 | 32.2 |
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