Year | Value | 2021 | 59.029 | 2020 | 59.584 | 2019 | 59.977 | 2018 | 59.582 | 2017 | 59.331 | 2016 | 58.741 | 2015 | 58.213 | 2014 | 57.606 | 2013 | 56.925 | 2012 | 56.22 | 2011 | 55.314 | 2010 | 54.415 | 2009 | 53.537 | 2008 | 52.527 | 2007 | 51.473 | 2006 | 50.227 | 2005 | 49.508 | 2004 | 48.532 | 2003 | 47.568 | 2002 | 44.94 | 2001 | 43.714 | 2000 | 43.562 | 1999 | 42.455 | 1998 | 42.582 | 1997 | 44.35 | 1996 | 44.118 | 1995 | 43.885 | 1994 | 39.733 | 1993 | 38.161 | 1992 | 39.189 | 1991 | 41.009 | 1990 | 38.674 | 1989 | 38.557 | 1988 | 38.322 | 1987 | 37.575 | 1986 | 39.948 | 1985 | 39.712 | 1984 | 39.367 | 1983 | 39.118 | 1982 | 40.274 | 1981 | 39.997 | 1980 | 39.63 | 1979 | 39.344 | 1978 | 38.99 | 1977 | 38.575 | 1976 | 38.303 | 1975 | 38.397 | 1974 | 39.026 | 1973 | 38.642 | 1972 | 38.313 | 1971 | 37.933 | 1970 | 37.543 | 1969 | 37.192 | 1968 | 36.837 | 1967 | 36.466 | 1966 | 36.144 | 1965 | 35.884 | 1964 | 35.539 | 1963 | 35.247 | 1962 | 34.95 | 1961 | 34.704 | 1960 | 36.585 |
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