Year | Value | 2022 | 31.535 | 2021 | 31.751 | 2020 | 31.954 | 2019 | 32.145 | 2018 | 32.321 | 2017 | 32.484 | 2016 | 32.634 | 2015 | 32.77 | 2014 | 32.892 | 2013 | 33.014 | 2012 | 33.136 | 2011 | 33.259 | 2010 | 33.243 | 2009 | 33.158 | 2008 | 33.152 | 2007 | 33.223 | 2006 | 33.294 | 2005 | 33.365 | 2004 | 33.354 | 2003 | 33.263 | 2002 | 33.172 | 2001 | 33.081 | 2000 | 33.014 | 1999 | 32.954 | 1998 | 32.894 | 1997 | 32.834 | 1996 | 32.775 | 1995 | 32.715 | 1994 | 32.655 | 1993 | 32.596 | 1992 | 32.536 | 1991 | 32.477 | 1990 | 32.417 | 1989 | 32.358 | 1988 | 32.72 | 1987 | 33.46 | 1986 | 34.207 | 1985 | 34.962 | 1984 | 35.723 | 1983 | 36.494 | 1982 | 37.27 | 1981 | 38.054 | 1980 | 38.842 | 1979 | 39.639 | 1978 | 40.658 | 1977 | 41.868 | 1976 | 43.085 | 1975 | 44.315 | 1974 | 45.549 | 1973 | 46.79 | 1972 | 48.032 | 1971 | 49.281 | 1970 | 50.445 | 1969 | 51.47 | 1968 | 52.493 | 1967 | 53.516 | 1966 | 54.535 | 1965 | 55.55 | 1964 | 56.559 | 1963 | 57.566 | 1962 | 58.565 | 1961 | 59.557 | 1960 | 60.54 |
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