Year | Value | 2021 | 56.953 | 2020 | 57.818 | 2019 | 58.335 | 2018 | 58.133 | 2017 | 57.723 | 2016 | 57.245 | 2015 | 56.737 | 2014 | 56.586 | 2013 | 56.087 | 2012 | 55.682 | 2011 | 55.475 | 2010 | 54.83 | 2009 | 54.208 | 2008 | 53.848 | 2007 | 53.478 | 2006 | 52.975 | 2005 | 52.387 | 2004 | 51.855 | 2003 | 51.059 | 2002 | 50.372 | 2001 | 50.194 | 2000 | 49.78 | 1999 | 46.745 | 1998 | 46.498 | 1997 | 48.239 | 1996 | 47.075 | 1995 | 48.522 | 1994 | 48.219 | 1993 | 47.838 | 1992 | 47.819 | 1991 | 47.688 | 1990 | 47.324 | 1989 | 47.08 | 1988 | 46.656 | 1987 | 46.52 | 1986 | 46.004 | 1985 | 45.817 | 1984 | 45.559 | 1983 | 45.362 | 1982 | 45.017 | 1981 | 44.837 | 1980 | 44.598 | 1979 | 44.194 | 1978 | 43.439 | 1977 | 43.705 | 1976 | 43.625 | 1975 | 43.367 | 1974 | 43.245 | 1973 | 42.934 | 1972 | 42.813 | 1971 | 42.514 | 1970 | 42.075 | 1969 | 41.759 | 1968 | 41.547 | 1967 | 41.04 | 1966 | 40.902 | 1965 | 38.884 | 1964 | 38.17 | 1963 | 39.058 | 1962 | 38.848 | 1961 | 38.641 | 1960 | 39.663 |
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