Year | Value | 2021 | 57.618 | 2020 | 57.385 | 2019 | 58.523 | 2018 | 58.14 | 2017 | 58.059 | 2016 | 57.777 | 2015 | 57.288 | 2014 | 56.858 | 2013 | 56.281 | 2012 | 56.101 | 2011 | 55.808 | 2010 | 55.453 | 2009 | 55.01 | 2008 | 54.492 | 2007 | 54.15 | 2006 | 53.756 | 2005 | 53.166 | 2004 | 52.74 | 2003 | 52.208 | 2002 | 51.663 | 2001 | 50.954 | 2000 | 50.37 | 1999 | 49.669 | 1998 | 48.963 | 1997 | 48.306 | 1996 | 47.659 | 1995 | 47.45 | 1994 | 47.163 | 1993 | 47.136 | 1992 | 47.088 | 1991 | 46.844 | 1990 | 46.14 | 1989 | 45.508 | 1988 | 44.804 | 1987 | 44.169 | 1986 | 43.538 | 1985 | 42.773 | 1984 | 42.192 | 1983 | 41.679 | 1982 | 41.142 | 1981 | 40.498 | 1980 | 39.898 | 1979 | 38.972 | 1978 | 38.026 | 1977 | 37.061 | 1976 | 36.126 | 1975 | 35.134 | 1974 | 34.361 | 1973 | 33.609 | 1972 | 32.992 | 1971 | 32.175 | 1970 | 31.791 | 1969 | 31.299 | 1968 | 30.908 | 1967 | 30.485 | 1966 | 30.167 | 1965 | 29.857 | 1964 | 29.74 | 1963 | 29.456 | 1962 | 29.209 | 1961 | 29.118 | 1960 | 29.035 |
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