Year | Value | 2021 | 9.113 | 2020 | 9.296 | 2019 | 9.065 | 2018 | 9.308 | 2017 | 9.88 | 2016 | 10.046 | 2015 | 10.712 | 2014 | 11.219 | 2013 | 11.372 | 2012 | 11.939 | 2011 | 12.481 | 2010 | 13.089 | 2009 | 13.805 | 2008 | 14.546 | 2007 | 15.345 | 2006 | 16.096 | 2005 | 16.89 | 2004 | 17.491 | 2003 | 18.104 | 2002 | 18.67 | 2001 | 19.248 | 2000 | 19.794 | 1999 | 21.883 | 1998 | 21.608 | 1997 | 21.052 | 1996 | 21.18 | 1995 | 21.967 | 1994 | 21.92 | 1993 | 21.48 | 1992 | 21.506 | 1991 | 21.667 | 1990 | 21.34 | 1989 | 21.446 | 1988 | 21.521 | 1987 | 21.601 | 1986 | 21.837 | 1985 | 21.82 | 1984 | 21.851 | 1983 | 21.974 | 1982 | 22.18 | 1981 | 22.38 | 1980 | 22.616 | 1979 | 22.875 | 1978 | 23.242 | 1977 | 23.582 | 1976 | 23.958 | 1975 | 24.362 | 1974 | 24.773 | 1973 | 25.165 | 1972 | 25.574 | 1971 | 26.024 | 1970 | 26.472 | 1969 | 26.988 | 1968 | 27.387 | 1967 | 27.785 | 1966 | 28.292 | 1965 | 28.747 | 1964 | 29.178 | 1963 | 29.599 | 1962 | 29.951 | 1961 | 30.298 | 1960 | 30.608 |
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