Year | Value | 2021 | 59.411 | 2020 | 59.528 | 2019 | 59.892 | 2018 | 59.525 | 2017 | 59.391 | 2016 | 59.255 | 2015 | 57.898 | 2014 | 58.002 | 2013 | 58.736 | 2012 | 58.651 | 2011 | 58.368 | 2010 | 58.193 | 2009 | 57.811 | 2008 | 57.386 | 2007 | 56.857 | 2006 | 56.158 | 2005 | 55.267 | 2004 | 54.332 | 2003 | 50.619 | 2002 | 52.083 | 2001 | 50.978 | 2000 | 49.516 | 1999 | 47.828 | 1998 | 47.015 | 1997 | 45.962 | 1996 | 41.912 | 1995 | 41.548 | 1994 | 39.057 | 1993 | 39.73 | 1992 | 40.275 | 1991 | 40.872 | 1990 | 31.206 | 1989 | 41.882 | 1988 | 42.535 | 1987 | 43.142 | 1986 | 43.632 | 1985 | 43.055 | 1984 | 44.04 | 1983 | 44.023 | 1982 | 43.826 | 1981 | 43.568 | 1980 | 43.142 | 1979 | 42.929 | 1978 | 42.578 | 1977 | 42.136 | 1976 | 41.683 | 1975 | 41.307 | 1974 | 40.845 | 1973 | 40.34 | 1972 | 39.906 | 1971 | 39.345 | 1970 | 39.017 | 1969 | 38.606 | 1968 | 38.175 | 1967 | 37.877 | 1966 | 37.456 | 1965 | 37.208 | 1964 | 37.014 | 1963 | 36.865 | 1962 | 36.773 | 1961 | 36.723 | 1960 | 36.728 |
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