Year | Value | 2021 | 52.285 | 2020 | 52.456 | 2019 | 52.651 | 2018 | 52.331 | 2017 | 52.017 | 2016 | 51.848 | 2015 | 51.477 | 2014 | 51.383 | 2013 | 51.295 | 2012 | 51.094 | 2011 | 50.92 | 2010 | 50.483 | 2009 | 50.182 | 2008 | 49.678 | 2007 | 49.258 | 2006 | 48.901 | 2005 | 48.362 | 2004 | 47.785 | 2003 | 47.377 | 2002 | 46.867 | 2001 | 46.58 | 2000 | 46.095 | 1999 | 45.446 | 1998 | 44.89 | 1997 | 44.385 | 1996 | 44.052 | 1995 | 44.004 | 1994 | 44.079 | 1993 | 44.232 | 1992 | 44.145 | 1991 | 44.197 | 1990 | 44.597 | 1989 | 44.788 | 1988 | 44.729 | 1987 | 44.745 | 1986 | 44.841 | 1985 | 45.126 | 1984 | 45.473 | 1983 | 45.571 | 1982 | 45.434 | 1981 | 45.504 | 1980 | 45.23 | 1979 | 45.187 | 1978 | 44.957 | 1977 | 44.597 | 1976 | 43.887 | 1975 | 42.922 | 1974 | 42.106 | 1973 | 41.331 | 1972 | 40.488 | 1971 | 39.68 | 1970 | 38.78 | 1969 | 37.244 | 1968 | 36.911 | 1967 | 35.94 | 1966 | 37.784 | 1965 | 37.582 | 1964 | 37.22 | 1963 | 37.069 | 1962 | 36.679 | 1961 | 36.487 | 1960 | 36.2 |
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