Year Measure 1971 579.09637 1972 585.45392 1973 597.13822 1974 600.42648 1975 608.45573 1976 622.29176 1977 636.23685 1978 645.89238 1979 653.16389 1980 665.10006 1981 676.38694 1982 691.78086 1983 693.55611 1984 677.76523 1985 682.81944 1986 671.49901 1987 676.8561 1988 678.85595 1989 684.44825 1990 697.19208 1991 712.24816 1992 721.97035 1993 715.4378 1994 680.71007 1995 682.26958 1996 693.7783 1997 699.6507 1998 687.11792 1999 694.1713 2000 703.24472 2001 720.04724 2002 724.61125 2003 746.61221 2004 748.34132 2005 757.95866 2006 744.54523 2007 750.78312 2008 752.85979 2009 721.45336 2010 755.98915 2011 778.49939 2012 798.30312 2013 779.85154 2014 763.39137