Year Measure 1971 295.59613 1972 343.58635 1973 397.08943 1974 458.94955 1975 501.71871 1976 577.93176 1977 659.23693 1978 779.51407 1979 880.55609 1980 913.62936 1981 971.79348 1982 1027.8604 1983 1140.70509 1984 1250.23648 1985 1340.12996 1986 1480.0185 1987 1674.24725 1988 1920.52356 1989 2095.19471 1990 2373.21441 1991 2588.84808 1992 2826.18879 1993 3091.3712 1994 3495.48873 1995 3881.02444 1996 4280.71094 1997 4651.62888 1998 4436.17441 1999 4878.83338 2000 5906.95933 2001 6309.2034 2002 6673.9377 2003 6977.31766 2004 7390.79415 2005 7796.31467 2006 8039.79628 2007 8462.20654 2008 8772.28746 2009 8877.57493 2010 9716.12608 2011 10129.95709 2012 10305.32898 2013 10384.62216 2014 10496.51367