Year Measure 1971 231.57993 1972 261.46528 1973 305.12734 1974 319.22244 1975 330.39705 1976 366.5219 1977 398.65611 1978 476.77836 1979 586.3413 1980 579.45155 1981 610.8346 1982 771.2355 1983 807.84306 1984 776.33759 1985 786.32601 1986 862.41416 1987 827.55223 1988 849.70713 1989 820.31048 1990 856.15888 1991 883.72536 1992 883.74026 1993 867.5753 1994 819.26503 1995 838.76879 1996 798.14484 1997 804.86635 1998 820.64758 1999 863.78721 2000 865.66596 2001 856.21274 2002 904.32469 2003 948.95949 2004 948.23819 2005 973.87895 2006 1027.73647 2007 1073.99966 2008 1069.20022 2009 1149.37419 2010 1109.89246 2011 1135.74446 2012 1223.59179 2013 1241.03836 2014 1321.09949