Year | Value | 2021 | 6.327 | 2020 | 5.851 | 2019 | 5.581 | 2018 | 5.511 | 2017 | 5.482 | 2016 | 5.662 | 2015 | 5.823 | 2014 | 5.823 | 2013 | 5.964 | 2012 | 5.91 | 2011 | 5.956 | 2010 | 6.018 | 2009 | 6.05 | 2008 | 6.08 | 2007 | 6.128 | 2006 | 6.151 | 2005 | 6.206 | 2004 | 6.248 | 2003 | 6.318 | 2002 | 6.202 | 2001 | 6.285 | 2000 | 6.384 | 1999 | 6.48 | 1998 | 6.57 | 1997 | 6.653 | 1996 | 6.836 | 1995 | 7.025 | 1994 | 7.264 | 1993 | 7.453 | 1992 | 7.684 | 1991 | 7.834 | 1990 | 8.194 | 1989 | 8.536 | 1988 | 8.935 | 1987 | 9.428 | 1986 | 9.944 | 1985 | 10.397 | 1984 | 10.901 | 1983 | 11.427 | 1982 | 11.992 | 1981 | 12.521 | 1980 | 12.892 | 1979 | 13.411 | 1978 | 13.876 | 1977 | 14.38 | 1976 | 14.839 | 1975 | 15.31 | 1974 | 15.772 | 1973 | 16.378 | 1972 | 16.537 | 1971 | 16.813 | 1970 | 17.09 | 1969 | 17.304 | 1968 | 17.341 | 1967 | 17.63 | 1966 | 17.774 | 1965 | 18.127 | 1964 | 18.705 | 1963 | 19.349 | 1962 | 20.024 | 1961 | 20.738 | 1960 | 21.364 |
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