Year Measure 1971 403.63549 1972 389.47063 1973 420.83247 1974 459.26926 1975 441.65335 1976 456.17876 1977 498.24114 1978 551.69076 1979 589.37404 1980 618.03525 1981 614.60409 1982 638.33316 1983 642.29931 1984 696.17595 1985 729.37017 1986 781.28118 1987 757.69564 1988 776.48475 1989 821.93181 1990 841.86409 1991 842.28877 1992 753.82434 1993 846.1903 1994 883.97266 1995 895.38541 1996 887.80168 1997 895.86316 1998 874.44425 1999 810.68771 2000 829.39894 2001 850.42517 2002 858.62067 2003 862.51826 2004 898.34411 2005 895.81684 2006 947.12709 2007 974.38686 2008 974.2204 2009 1049.9782 2010 1077.98457 2011 1121.3911 2012 1149.96382 2013 1287.20243 2014 1289.56969