Year | Value | 2021 | 8.582 | 2020 | 8.419 | 2019 | 8.16 | 2018 | 8.379 | 2017 | 8.594 | 2016 | 8.886 | 2015 | 9.179 | 2014 | 9.548 | 2013 | 9.833 | 2012 | 10.235 | 2011 | 10.641 | 2010 | 10.992 | 2009 | 11.3 | 2008 | 11.583 | 2007 | 11.886 | 2006 | 12.104 | 2005 | 12.408 | 2004 | 12.565 | 2003 | 12.758 | 2002 | 13.036 | 2001 | 13.237 | 2000 | 13.426 | 1999 | 13.614 | 1998 | 13.723 | 1997 | 13.713 | 1996 | 13.756 | 1995 | 13.64 | 1994 | 13.561 | 1993 | 13.356 | 1992 | 13.199 | 1991 | 13.153 | 1990 | 13.09 | 1989 | 13.11 | 1988 | 13.204 | 1987 | 13.408 | 1986 | 13.867 | 1985 | 14.038 | 1984 | 14.528 | 1983 | 14.935 | 1982 | 15.412 | 1981 | 15.807 | 1980 | 16.157 | 1979 | 16.472 | 1978 | 16.677 | 1977 | 16.859 | 1976 | 16.926 | 1975 | 17.03 | 1974 | 17.144 | 1973 | 17.331 | 1972 | 17.642 | 1971 | 18.112 | 1970 | 18.599 | 1969 | 19.165 | 1968 | 19.802 | 1967 | 20.413 | 1966 | 20.973 | 1965 | 21.384 | 1964 | 21.794 | 1963 | 22.049 | 1962 | 22.284 | 1961 | 28.151 | 1960 | 28.64 |
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