Year | Value | 2021 | 27.685 | 2020 | 27.998 | 2019 | 28.46 | 2018 | 29.18 | 2017 | 29.755 | 2016 | 30.401 | 2015 | 30.957 | 2014 | 31.298 | 2013 | 32.127 | 2012 | 33.174 | 2011 | 34.24 | 2010 | 35.422 | 2009 | 36.563 | 2008 | 37.546 | 2007 | 38.098 | 2006 | 38.29 | 2005 | 38.502 | 2004 | 38.732 | 2003 | 39.045 | 2002 | 39.594 | 2001 | 39.983 | 2000 | 39.934 | 1999 | 39.987 | 1998 | 40.242 | 1997 | 40.075 | 1996 | 40.22 | 1995 | 40.428 | 1994 | 40.599 | 1993 | 41.064 | 1992 | 41.712 | 1991 | 42.541 | 1990 | 43.522 | 1989 | 44.538 | 1988 | 45.389 | 1987 | 46.191 | 1986 | 46.62 | 1985 | 46.886 | 1984 | 47.317 | 1983 | 47.532 | 1982 | 48.081 | 1981 | 48.52 | 1980 | 48.569 | 1979 | 48.95 | 1978 | 49.188 | 1977 | 49.425 | 1976 | 49.778 | 1975 | 50.031 | 1974 | 50.436 | 1973 | 51.018 | 1972 | 51.735 | 1971 | 52.41 | 1970 | 52.749 | 1969 | 53.367 | 1968 | 53.842 | 1967 | 54.369 | 1966 | 54.922 | 1965 | 55.294 | 1964 | 55.229 | 1963 | 55.453 | 1962 | 55.581 | 1961 | 55.45 | 1960 | 55.169 |
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