Year | Value | 2022 | 38.187 | 2021 | 37.628 | 2020 | 37.074 | 2019 | 36.528 | 2018 | 35.988 | 2017 | 35.455 | 2016 | 34.926 | 2015 | 34.4 | 2014 | 33.878 | 2013 | 33.36 | 2012 | 32.846 | 2011 | 32.336 | 2010 | 31.83 | 2009 | 31.328 | 2008 | 30.832 | 2007 | 30.364 | 2006 | 30.182 | 2005 | 29.999 | 2004 | 29.818 | 2003 | 29.637 | 2002 | 29.457 | 2001 | 29.277 | 2000 | 29.098 | 1999 | 28.92 | 1998 | 28.742 | 1997 | 28.535 | 1996 | 28.013 | 1995 | 27.495 | 1994 | 26.984 | 1993 | 26.479 | 1992 | 25.98 | 1991 | 25.487 | 1990 | 25 | 1989 | 23.545 | 1988 | 22.152 | 1987 | 20.815 | 1986 | 19.541 | 1985 | 18.326 | 1984 | 17.172 | 1983 | 16.074 | 1982 | 15.035 | 1981 | 14.051 | 1980 | 13.158 | 1979 | 12.669 | 1978 | 12.197 | 1977 | 11.739 | 1976 | 11.297 | 1975 | 10.869 | 1974 | 10.456 | 1973 | 10.056 | 1972 | 9.671 | 1971 | 9.298 | 1970 | 8.99 | 1969 | 8.753 | 1968 | 8.522 | 1967 | 8.296 | 1966 | 8.075 | 1965 | 7.86 | 1964 | 7.65 | 1963 | 7.445 | 1962 | 7.246 | 1961 | 7.051 | 1960 | 6.868 |
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