Year | Value | 2021 | 58.598 | 2020 | 59.032 | 2019 | 59.319 | 2018 | 58.849 | 2017 | 58.48 | 2016 | 58.06 | 2015 | 57.762 | 2014 | 57.208 | 2013 | 56.748 | 2012 | 56.158 | 2011 | 55.52 | 2010 | 55.023 | 2009 | 54.394 | 2008 | 53.653 | 2007 | 52.97 | 2006 | 52.355 | 2005 | 51.824 | 2004 | 51.363 | 2003 | 50.954 | 2002 | 50.886 | 2001 | 50.81 | 2000 | 50.842 | 1999 | 50.957 | 1998 | 51.108 | 1997 | 51.449 | 1996 | 51.52 | 1995 | 51.61 | 1994 | 51.737 | 1993 | 51.925 | 1992 | 52.138 | 1991 | 52.323 | 1990 | 52.603 | 1989 | 52.876 | 1988 | 53.017 | 1987 | 53.187 | 1986 | 53.202 | 1985 | 53.174 | 1984 | 53.037 | 1983 | 53.171 | 1982 | 52.919 | 1981 | 52.734 | 1980 | 52.27 | 1979 | 51.682 | 1978 | 50.927 | 1977 | 50.184 | 1976 | 49.291 | 1975 | 48.346 | 1974 | 47.506 | 1973 | 46.556 | 1972 | 45.724 | 1971 | 44.992 | 1970 | 44.325 | 1969 | 43.643 | 1968 | 43.021 | 1967 | 42.419 | 1966 | 41.819 | 1965 | 41.177 | 1964 | 40.606 | 1963 | 39.955 | 1962 | 39.402 | 1961 | 38.744 | 1960 | 38.108 |
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