Year | Value | 2021 | 35.842 | 2020 | 36.051 | 2019 | 36.466 | 2018 | 36.927 | 2017 | 37.342 | 2016 | 37.936 | 2015 | 38.803 | 2014 | 39.105 | 2013 | 39.601 | 2012 | 40.009 | 2011 | 39.855 | 2010 | 40.602 | 2009 | 41.157 | 2008 | 41.506 | 2007 | 43.858 | 2006 | 44.721 | 2005 | 45.263 | 2004 | 46.33 | 2003 | 47.35 | 2002 | 48.201 | 2001 | 48.979 | 2000 | 49.664 | 1999 | 50.351 | 1998 | 50.88 | 1997 | 51.4 | 1996 | 51.873 | 1995 | 52.073 | 1994 | 52.174 | 1993 | 52.038 | 1992 | 51.948 | 1991 | 51.788 | 1990 | 51.423 | 1989 | 51.162 | 1988 | 50.98 | 1987 | 50.845 | 1986 | 50.728 | 1985 | 50.553 | 1984 | 50.235 | 1983 | 50.139 | 1982 | 50.138 | 1981 | 50.264 | 1980 | 50.482 | 1979 | 50.737 | 1978 | 50.816 | 1977 | 50.921 | 1976 | 50.935 | 1975 | 51.018 | 1974 | 51.135 | 1973 | 51.114 | 1972 | 51.109 | 1971 | 51.163 | 1970 | 51.122 | 1969 | 51.195 | 1968 | 51.148 | 1967 | 51.081 | 1966 | 50.986 | 1965 | 50.872 | 1964 | 50.831 | 1963 | 50.703 | 1962 | 50.57 | 1961 | 50.443 | 1960 | 50.34 |
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