Year | Value | 2021 | 43.357 | 2020 | 43.849 | 2019 | 44.229 | 2018 | 44.37 | 2017 | 44.811 | 2016 | 45.456 | 2015 | 46.367 | 2014 | 46.998 | 2013 | 47.46 | 2012 | 48.019 | 2011 | 48.357 | 2010 | 48.764 | 2009 | 48.922 | 2008 | 49.234 | 2007 | 49.711 | 2006 | 49.923 | 2005 | 50.317 | 2004 | 50.29 | 2003 | 49.949 | 2002 | 50.307 | 2001 | 51.08 | 2000 | 51.324 | 1999 | 51.727 | 1998 | 52.22 | 1997 | 52.384 | 1996 | 52.957 | 1995 | 52.08 | 1994 | 52.058 | 1993 | 53.521 | 1992 | 53.269 | 1991 | 52.075 | 1990 | 52.362 | 1989 | 52.115 | 1988 | 51.658 | 1987 | 50.669 | 1986 | 49.367 | 1985 | 49.271 | 1984 | 50.371 | 1983 | 49.833 | 1982 | 46.901 | 1981 | 46.346 | 1980 | 48.206 | 1979 | 48.054 | 1978 | 48.179 | 1977 | 48.437 | 1976 | 48.643 | 1975 | 48.74 | 1974 | 48.831 | 1973 | 48.991 | 1972 | 48.972 | 1971 | 47.179 | 1970 | 46.708 | 1969 | 46.241 | 1968 | 45.815 | 1967 | 45.59 | 1966 | 45.441 | 1965 | 45.396 | 1964 | 45.43 | 1963 | 45.475 | 1962 | 45.589 | 1961 | 45.665 | 1960 | 45.749 |
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