Year | Value | 2022 | 50.466 | 2021 | 50.427 | 2020 | 50.416 | 2019 | 50.433 | 2018 | 50.478 | 2017 | 50.55 | 2016 | 50.65 | 2015 | 50.75 | 2014 | 50.85 | 2013 | 50.95 | 2012 | 51.05 | 2011 | 51.15 | 2010 | 50.956 | 2009 | 50.472 | 2008 | 49.989 | 2007 | 49.505 | 2006 | 49.021 | 2005 | 48.537 | 2004 | 48.054 | 2003 | 47.571 | 2002 | 47.088 | 2001 | 46.606 | 2000 | 46.126 | 1999 | 45.644 | 1998 | 45.164 | 1997 | 44.685 | 1996 | 44.208 | 1995 | 43.731 | 1994 | 43.255 | 1993 | 42.78 | 1992 | 42.308 | 1991 | 41.836 | 1990 | 41.365 | 1989 | 40.897 | 1988 | 40.685 | 1987 | 40.697 | 1986 | 40.71 | 1985 | 40.722 | 1984 | 40.734 | 1983 | 40.746 | 1982 | 40.758 | 1981 | 40.77 | 1980 | 40.782 | 1979 | 40.794 | 1978 | 40.536 | 1977 | 40.051 | 1976 | 39.568 | 1975 | 39.087 | 1974 | 38.608 | 1973 | 38.131 | 1972 | 37.657 | 1971 | 37.184 | 1970 | 36.714 | 1969 | 36.354 | 1968 | 36.087 | 1967 | 35.82 | 1966 | 35.554 | 1965 | 35.289 | 1964 | 35.025 | 1963 | 34.762 | 1962 | 34.5 | 1961 | 34.238 | 1960 | 33.978 |
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