Year | Value | 2021 | 55.28 | 2020 | 55.967 | 2019 | 57.078 | 2018 | 56.375 | 2017 | 55.654 | 2016 | 55.044 | 2015 | 54.857 | 2014 | 54.277 | 2013 | 53.843 | 2012 | 53.161 | 2011 | 51.304 | 2010 | 50.563 | 2009 | 51.853 | 2008 | 51.12 | 2007 | 50.515 | 2006 | 50.597 | 2005 | 50.661 | 2004 | 50.538 | 2003 | 50.614 | 2002 | 50.731 | 2001 | 50.74 | 2000 | 50.66 | 1999 | 50.525 | 1998 | 50.66 | 1997 | 50.195 | 1996 | 50.447 | 1995 | 50.6 | 1994 | 50.327 | 1993 | 50.648 | 1992 | 27.312 | 1991 | 26.565 | 1990 | 47.105 | 1989 | 46.717 | 1988 | 43.835 | 1987 | 48.903 | 1986 | 48.37 | 1985 | 48.281 | 1984 | 48.459 | 1983 | 48.166 | 1982 | 47.83 | 1981 | 47.666 | 1980 | 47.489 | 1979 | 47.305 | 1978 | 46.95 | 1977 | 46.918 | 1976 | 44.568 | 1975 | 44.182 | 1974 | 43.818 | 1973 | 46.131 | 1972 | 45.94 | 1971 | 45.747 | 1970 | 45.557 | 1969 | 45.37 | 1968 | 45.173 | 1967 | 44.97 | 1966 | 44.76 | 1965 | 44.544 | 1964 | 44.3 | 1963 | 44.1 | 1962 | 43.877 | 1961 | 43.563 | 1960 | 43.452 |
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