Year | Value | 2021 | 59.493 | 2020 | 60.014 | 2019 | 60.402 | 2018 | 59.724 | 2017 | 59.449 | 2016 | 58.86 | 2015 | 58.187 | 2014 | 57.577 | 2013 | 56.868 | 2012 | 56.116 | 2011 | 55.084 | 2010 | 54.331 | 2009 | 53.551 | 2008 | 52.82 | 2007 | 51.967 | 2006 | 51.232 | 2005 | 50.139 | 2004 | 48.769 | 2003 | 47.161 | 2002 | 45.532 | 2001 | 44.186 | 2000 | 42.781 | 1999 | 41.696 | 1998 | 40.865 | 1997 | 41.098 | 1996 | 41.307 | 1995 | 41.343 | 1994 | 41.33 | 1993 | 41.182 | 1992 | 41.284 | 1991 | 41.177 | 1990 | 41.251 | 1989 | 41.29 | 1988 | 41.382 | 1987 | 41.83 | 1986 | 42.291 | 1985 | 42.84 | 1984 | 43.388 | 1983 | 43.738 | 1982 | 43.691 | 1981 | 43.461 | 1980 | 42.906 | 1979 | 42.176 | 1978 | 41.271 | 1977 | 40.391 | 1976 | 39.607 | 1975 | 38.897 | 1974 | 38.194 | 1973 | 37.33 | 1972 | 36.576 | 1971 | 35.899 | 1970 | 35.362 | 1969 | 34.942 | 1968 | 34.669 | 1967 | 34.352 | 1966 | 34.202 | 1965 | 34.088 | 1964 | 33.944 | 1963 | 33.776 | 1962 | 33.624 | 1961 | 33.373 | 1960 | 33.422 |
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