Year | Value | 2021 | 31.287 | 2020 | 31.708 | 2019 | 32.181 | 2018 | 32.706 | 2017 | 33.151 | 2016 | 33.713 | 2015 | 34.215 | 2014 | 35.075 | 2013 | 36.138 | 2012 | 37.307 | 2011 | 37.395 | 2010 | 38.074 | 2009 | 38.94 | 2008 | 39.876 | 2007 | 40.863 | 2006 | 41.332 | 2005 | 41.482 | 2004 | 41.457 | 2003 | 41.746 | 2002 | 42.318 | 2001 | 43.041 | 2000 | 43.606 | 1999 | 44.068 | 1998 | 44.27 | 1997 | 44.386 | 1996 | 44.587 | 1995 | 44.661 | 1994 | 44.565 | 1993 | 44.597 | 1992 | 44.527 | 1991 | 44.629 | 1990 | 44.441 | 1989 | 44.461 | 1988 | 44.723 | 1987 | 44.988 | 1986 | 45.479 | 1985 | 45.744 | 1984 | 45.884 | 1983 | 46.453 | 1982 | 46.899 | 1981 | 47.486 | 1980 | 48.044 | 1979 | 48.498 | 1978 | 48.583 | 1977 | 48.685 | 1976 | 48.653 | 1975 | 48.621 | 1974 | 48.467 | 1973 | 48.387 | 1972 | 48.2 | 1971 | 48.036 | 1970 | 48.48 | 1969 | 49.063 | 1968 | 48.964 | 1967 | 49.031 | 1966 | 49.014 | 1965 | 49.084 | 1964 | 49.024 | 1963 | 48.924 | 1962 | 48.696 | 1961 | 48.378 | 1960 | 48.044 |
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