Year | Value | 2022 | 36.868 | 2021 | 36.694 | 2020 | 36.537 | 2019 | 36.396 | 2018 | 36.272 | 2017 | 36.164 | 2016 | 36.072 | 2015 | 35.997 | 2014 | 35.938 | 2013 | 35.896 | 2012 | 35.869 | 2011 | 35.859 | 2010 | 35.865 | 2009 | 35.871 | 2008 | 35.877 | 2007 | 35.883 | 2006 | 35.889 | 2005 | 35.895 | 2004 | 35.901 | 2003 | 35.907 | 2002 | 35.913 | 2001 | 35.919 | 2000 | 35.698 | 1999 | 35.45 | 1998 | 35.204 | 1997 | 34.959 | 1996 | 34.714 | 1995 | 34.47 | 1994 | 34.227 | 1993 | 33.985 | 1992 | 33.744 | 1991 | 33.503 | 1990 | 33.427 | 1989 | 33.377 | 1988 | 33.327 | 1987 | 33.277 | 1986 | 33.227 | 1985 | 33.177 | 1984 | 33.128 | 1983 | 33.078 | 1982 | 33.028 | 1981 | 32.978 | 1980 | 32.912 | 1979 | 32.841 | 1978 | 32.771 | 1977 | 32.701 | 1976 | 32.631 | 1975 | 32.561 | 1974 | 32.491 | 1973 | 32.421 | 1972 | 32.351 | 1971 | 32.281 | 1970 | 32.212 | 1969 | 32.04 | 1968 | 31.848 | 1967 | 31.656 | 1966 | 31.465 | 1965 | 31.274 | 1964 | 31.085 | 1963 | 30.895 | 1962 | 30.707 | 1961 | 30.519 | 1960 | 30.332 |
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