Year Measure 1971 320.07711 1972 342.17613 1973 348.9188 1974 380.14216 1975 384.48177 1976 400.97835 1977 425.47412 1978 456.38739 1979 483.67775 1980 513.16792 1981 515.16725 1982 492.69843 1983 544.16615 1984 560.59737 1985 568.4494 1986 546.54585 1987 542.11587 1988 556.52923 1989 541.5855 1990 600.88109 1991 581.99773 1992 633.238 1993 603.61054 1994 639.86832 1995 636.85966 1996 655.47199 1997 666.83191 1998 717.98467 1999 734.08126 2000 753.24895 2001 787.99935 2002 792.11068 2003 807.63029 2004 844.78639 2005 823.00815 2006 858.33741 2007 877.71612 2008 905.79549 2009 870.36471 2010 966.33437 2011 911.90727 2012 940.97946 2013 945.35695 2014 943.60704