Year | Value | 2022 | 37.461 | 2021 | 37.146 | 2020 | 36.856 | 2019 | 36.591 | 2018 | 36.351 | 2017 | 36.135 | 2016 | 35.944 | 2015 | 35.777 | 2014 | 35.635 | 2013 | 35.517 | 2012 | 35.423 | 2011 | 35.352 | 2010 | 35.306 | 2009 | 35.284 | 2008 | 35.285 | 2007 | 35.287 | 2006 | 35.289 | 2005 | 35.29 | 2004 | 35.292 | 2003 | 35.293 | 2002 | 35.295 | 2001 | 35.296 | 2000 | 35.298 | 1999 | 35.3 | 1998 | 35.504 | 1997 | 35.785 | 1996 | 36.066 | 1995 | 36.349 | 1994 | 36.633 | 1993 | 36.918 | 1992 | 37.203 | 1991 | 37.49 | 1990 | 37.777 | 1989 | 38.065 | 1988 | 38.227 | 1987 | 38.277 | 1986 | 38.327 | 1985 | 38.377 | 1984 | 38.427 | 1983 | 38.477 | 1982 | 38.527 | 1981 | 38.577 | 1980 | 38.627 | 1979 | 38.677 | 1978 | 38.621 | 1977 | 38.476 | 1976 | 38.331 | 1975 | 38.186 | 1974 | 38.042 | 1973 | 37.897 | 1972 | 37.753 | 1971 | 37.609 | 1970 | 37.466 | 1969 | 37.214 | 1968 | 36.871 | 1967 | 36.53 | 1966 | 36.19 | 1965 | 35.851 | 1964 | 35.515 | 1963 | 35.178 | 1962 | 34.844 | 1961 | 34.511 | 1960 | 34.181 |
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