Year Measure 1971 1182.37949 1972 1118.91206 1973 1175.46446 1974 1226.389 1975 1242.58559 1976 1290.26512 1977 1389.87221 1978 1460.99066 1979 1487.92027 1980 1488.69502 1981 1489.85205 1982 1503.68536 1983 1578.04558 1984 1536.1951 1985 1516.8153 1986 1498.92817 1987 1547.19269 1988 1607.89776 1989 1746.40312 1990 1645.06414 1991 1350.82761 1992 1175.85234 1993 976.6098 1994 1001.23569 1995 995.89897 1996 1082.02254 1997 1106.34863 1998 1032.40798 1999 1069.67144 2000 1142.28935 2001 1112.48525 2002 1033.7242 2003 1026.13588 2004 1000.96175 2005 945.5318 2006 943.04659 2007 897.14409 2008 952.04193 2009 1008.40121 2010 1089.10072 2011 1022.08804 2012 1053.63971 2013 1010.56627 2014 1022.66891