Year Measure 1971 7641.88496 1972 7913.63485 1973 7846.63519 1974 7060.32748 1975 6323.89603 1976 6455.75 1977 6562.85171 1978 6743.8109 1979 8023.84658 1980 7617.56969 1981 7136.66059 1982 7585.79223 1983 7704.41935 1984 7609.60556 1985 8066.30328 1986 8271.50463 1987 8506.31971 1988 9894.82487 1989 11237.83365 1990 4338.50873 1991 1322.22507 1995 9183.84926 1996 8915.13967 1997 8566.77961 1998 9142.51127 1999 9206.81367 2000 9126.90876 2001 9470.08967 2002 9582.17781 2003 10096.45349 2004 10583.84403 2005 11544.15553 2006 10795.26875 2007 10491.59147 2008 10825.76517 2009 11142.56073 2010 10699.31686 2011 10147.53446 2012 10953.22445 2013 9708.27302 2014 8956.82031