Year Measure 1971 1036.21417 1972 1145.8171 1973 1124.57663 1974 1155.40498 1975 1133.97068 1976 1263.57909 1977 1398.39829 1978 1477.06704 1979 1734.93877 1980 1875.04377 1981 2073.36407 1982 2405.83039 1983 2551.2086 1984 2601.03228 1985 2581.71297 1986 2779.44109 1987 2912.36874 1988 2620.14967 1989 2518.07809 1990 2682.70726 1991 2648.16771 1992 2846.0905 1993 2814.19182 1994 2888.06528 1995 3101.19275 1996 3251.0466 1997 3638.51832 1998 3763.04313 1999 3810.16386 2000 3990.58663 2001 4099.40427 2002 4081.89777 2003 4770.05604 2004 4697.27671 2005 5142.12751 2006 5307.16483 2007 5668.85111 2008 5707.13076 2009 5714.20789 2010 6189.29297 2011 6389.77875 2012 6628.71165 2013 6876.33136 2014 7134.03465