Year | Value | 2023 | 33.879 | 2022 | 34.35 | 2021 | 34.779 | 2020 | 35.331 | 2019 | 36.036 | 2018 | 36.955 | 2017 | 37.84 | 2016 | 38.554 | 2015 | 38.996 | 2014 | 39.342 | 2013 | 39.582 | 2012 | 39.706 | 2011 | 39.691 | 2010 | 39.77 | 2009 | 39.982 | 2008 | 40.371 | 2007 | 40.961 | 2006 | 41.341 | 2005 | 41.087 | 2004 | 41.329 | 2003 | 41.475 | 2002 | 41.48 | 2001 | 41.695 | 2000 | 42.079 | 1999 | 42.548 | 1998 | 43.007 | 1997 | 43.381 | 1996 | 43.738 | 1995 | 44.35 | 1994 | 45.699 | 1993 | 44.07 | 1992 | 44.924 | 1991 | 45.361 | 1990 | 45.713 | 1989 | 45.988 | 1988 | 46.592 | 1987 | 46.901 | 1986 | 47.092 | 1985 | 47.348 | 1984 | 47.564 | 1983 | 47.695 | 1982 | 48.046 | 1981 | 48.221 | 1980 | 47.92 | 1979 | 47.401 | 1978 | 46.893 | 1977 | 47.033 | 1976 | 47.077 | 1975 | 47.145 |
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