Year | Value | 2021 | 12.489612763836 | 2020 | 12.489612763836 | 2019 | 12.489612763836 | 2018 | 12.489612763836 | 2017 | 12.489612763836 | 2016 | 12.489612763836 | 2015 | 12.489612763836 | 2014 | 12.489612763836 | 2013 | 12.489612763836 | 2012 | 12.489612763836 | 2011 | 12.489612763836 | 2010 | 12.921721788267 | 2009 | 13.578195113844 | 2008 | 14.22635865049 | 2007 | 14.874522187136 | 2006 | 15.522685723783 | 2005 | 16.154229682566 | 2004 | 16.104370948978 | 2003 | 16.046202426458 | 2002 | 15.963104537145 | 2001 | 15.888316436762 | 2000 | 15.929865381419 | 1999 | 15.373109523018 | 1998 | 14.95762007645 | 1997 | 14.542130629882 | 1996 | 13.711151736746 | 1995 | 13.711151736746 | 1994 | 11.218215057338 | 1993 | 11.218215057338 | 1992 | 10.968921389397 | 1991 | 10.802725610769 | 1990 | 10.802725610769 | 1989 | 10.802725610769 | 1988 | 10.636529832142 | 1987 | 10.387236164201 | 1986 | 10.137942496261 | 1985 | 10.137942496261 | 1984 | 9.9717467176334 | 1983 | 9.5562572710653 | 1982 | 9.5562572710653 | 1981 | 9.5562572710653 | 1980 | 8.8914741565564 | 1979 | 8.8831643676251 | 1978 | 8.8499252118996 | 1977 | 8.8083762672428 | 1976 | 8.8083762672428 | 1975 | 8.8083762672428 | 1974 | 8.8083762672428 | 1973 | 8.7252783779292 | 1972 | 8.6421804886156 | 1971 | 8.6421804886156 | 1970 | 8.6421804886156 | 1969 | 8.6421804886156 | 1968 | 8.6421804886156 | 1967 | 8.6421804886156 | 1966 | 8.6421804886156 | 1965 | 8.559082599302 | 1964 | 8.559082599302 | 1963 | 8.559082599302 | 1962 | 8.559082599302 | 1961 | 8.559082599302 |
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