Year | Value | 2021 | 60.594 | 2020 | 60.708 | 2019 | 61.644 | 2018 | 61.191 | 2017 | 60.821 | 2016 | 60.479 | 2015 | 60.103 | 2014 | 59.595 | 2013 | 59.224 | 2012 | 58.865 | 2011 | 58.412 | 2010 | 57.878 | 2009 | 57.431 | 2008 | 57.074 | 2007 | 56.54 | 2006 | 56.046 | 2005 | 55.464 | 2004 | 55.036 | 2003 | 54.581 | 2002 | 54.085 | 2001 | 53.636 | 2000 | 53.226 | 1999 | 52.752 | 1998 | 52.382 | 1997 | 52.061 | 1996 | 51.727 | 1995 | 51.592 | 1994 | 51.415 | 1993 | 51.308 | 1992 | 51.113 | 1991 | 50.969 | 1990 | 50.86 | 1989 | 50.668 | 1988 | 50.504 | 1987 | 50.279 | 1986 | 50.039 | 1985 | 49.683 | 1984 | 49.208 | 1983 | 49.007 | 1982 | 48.596 | 1981 | 48.109 | 1980 | 47.563 | 1979 | 41.653 | 1978 | 40.793 | 1977 | 40.501 | 1976 | 28.921 | 1975 | 35.812 | 1974 | 40.186 | 1973 | 43.477 | 1972 | 43.284 | 1971 | 36.263 | 1970 | 30.248 | 1969 | 30.076 | 1968 | 43.731 | 1967 | 43.532 | 1966 | 43.264 | 1965 | 43.054 | 1964 | 42.749 | 1963 | 42.546 | 1962 | 42.258 | 1961 | 41.994 | 1960 | 41.729 |
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