Year Measure 1971 1292.24147 1972 1569.47082 1973 1711.83584 1974 1795.97901 1975 1640.48838 1976 1693.24729 1977 1763.23012 1978 2214.63035 1979 2130.84246 1980 2125.96683 1981 2124.85338 1982 1987.08731 1983 2195.89036 1984 2455.48438 1985 2472.96833 1986 2630.75438 1987 2757.88069 1988 2981.12861 1989 2896.50009 1990 3782.72028 1991 4167.36558 1992 4588.84551 1993 5487.60892 1994 6460.48198 1995 5346.87556 1996 5359.4098 1997 5818.34903 1998 5083.24962 1999 4587.49349 2000 4634.72585 2001 5145.88575 2002 5065.98451 2003 6216.73918 2004 7370.65288 2005 5055.96632 2006 5264.39866 2007 4677.20431 2008 5094.13571 2009 4257.77628 2010 5006.62099 2011 5069.17179 2012 4898.33046 2013 4880.40607 2014 5121.80432