Year | Value | 2021 | 21.95 | 2020 | 22.265 | 2019 | 22.6 | 2018 | 22.999 | 2017 | 23.377 | 2016 | 23.708 | 2015 | 24.441 | 2014 | 25.398 | 2013 | 26.207 | 2012 | 27.018 | 2011 | 27.84 | 2010 | 28.605 | 2009 | 29.044 | 2008 | 29.399 | 2007 | 29.085 | 2006 | 28.729 | 2005 | 28.605 | 2004 | 28.785 | 2003 | 29.068 | 2002 | 29.024 | 2001 | 29.153 | 2000 | 29.659 | 1999 | 30.551 | 1998 | 31.479 | 1997 | 32.784 | 1996 | 33.971 | 1995 | 34.843 | 1994 | 35.439 | 1993 | 35.883 | 1992 | 36.184 | 1991 | 36.572 | 1990 | 36.921 | 1989 | 37.915 | 1988 | 38.654 | 1987 | 39.329 | 1986 | 40.094 | 1985 | 40.509 | 1984 | 41.023 | 1983 | 41.685 | 1982 | 42.181 | 1981 | 42.865 | 1980 | 43.577 | 1979 | 44.03 | 1978 | 44.543 | 1977 | 45.418 | 1976 | 45.877 | 1975 | 46.445 | 1974 | 46.787 | 1973 | 47.285 | 1972 | 47.806 | 1971 | 48.184 | 1970 | 48.443 | 1969 | 48.886 | 1968 | 49.847 | 1967 | 50.308 | 1966 | 50.803 | 1965 | 51.318 | 1964 | 51.231 | 1963 | 51.307 | 1962 | 51.217 | 1961 | 51.033 | 1960 | 50.566 |
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