Year | Value | 2021 | 30.691 | 2020 | 31.155 | 2019 | 31.676 | 2018 | 32.337 | 2017 | 33.025 | 2016 | 33.706 | 2015 | 34.648 | 2014 | 35.527 | 2013 | 36.498 | 2012 | 37.508 | 2011 | 38.232 | 2010 | 38.858 | 2009 | 38.425 | 2008 | 38.209 | 2007 | 37.664 | 2006 | 37.498 | 2005 | 37.359 | 2004 | 37.403 | 2003 | 37.269 | 2002 | 37.547 | 2001 | 37.615 | 2000 | 37.158 | 1999 | 37.705 | 1998 | 37.973 | 1997 | 38.283 | 1996 | 38.222 | 1995 | 38.175 | 1994 | 38.313 | 1993 | 38.427 | 1992 | 38.626 | 1991 | 38.701 | 1990 | 38.847 | 1989 | 39.178 | 1988 | 39.464 | 1987 | 39.77 | 1986 | 40.04 | 1985 | 40.327 | 1984 | 40.649 | 1983 | 40.795 | 1982 | 40.935 | 1981 | 41.179 | 1980 | 41.474 | 1979 | 41.914 | 1978 | 42.381 | 1977 | 42.888 | 1976 | 43.264 | 1975 | 43.66 | 1974 | 43.896 | 1973 | 44.068 | 1972 | 44.284 | 1971 | 44.165 | 1970 | 43.95 | 1969 | 43.859 | 1968 | 43.791 | 1967 | 43.638 | 1966 | 43.571 | 1965 | 43.457 | 1964 | 43.276 | 1963 | 43.202 | 1962 | 43.072 | 1961 | 43.208 | 1960 | 43.357 |
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