| Year | Value | | 2021 | 6,109.6 | | 2020 | 6,104.9 | | 2019 | 6,122.8 | | 2018 | 6,120 | | 2017 | 6,150.4 | | 2016 | 6,174.8 | | 2015 | 6,164.9 | | 2014 | 6,148.4 | | 2013 | 6,102.1 | | 2012 | 6,117.9 | | 2011 | 6,206.1 | | 2010 | 6,238.6 | | 2009 | 6,251.2 | | 2008 | 6,185.6 | | 2007 | 4,980 | | 2006 | 4,910 | | 2005 | 5,090 | | 2004 | 4,920 | | 2003 | 5,100 | | 2002 | 5,050 | | 2001 | 5,100 | | 2000 | 5,180 | | 1999 | 5,000 | | 1998 | 4,900 | | 1997 | 4,950 | | 1996 | 5,250 | | 1995 | 5,380 | | 1994 | 5,490 | | 1993 | 5,600 | | 1992 | 5,640 | | 1991 | 5,640 | | 1990 | 5,640 | | 1989 | 5,640 | | 1988 | 5,640 | | 1987 | 5,640 | | 1986 | 5,640 | | 1985 | 5,640 | | 1984 | 5,640 | | 1983 | 5,640 | | 1982 | 5,640 | | 1981 | 5,640 | | 1980 | 5,640 | | 1979 | 5,640 | | 1978 | 5,640 | | 1977 | 5,640 | | 1976 | 5,640 | | 1975 | 5,640 | | 1974 | 5,640 | | 1973 | 5,640 | | 1972 | 5,640 | | 1971 | 5,640 | | 1970 | 5,640 | | 1969 | 5,640 | | 1968 | 5,640 | | 1967 | 5,640 | | 1966 | 5,640 | | 1965 | 5,640 | | 1964 | 5,640 | | 1963 | 5,640 | | 1962 | 5,640 | | 1961 | 5,640 |
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