Year Measure 1971 1934.56125 1972 1912.97138 1973 1980.84696 1974 1998.43101 1975 2059.00485 1976 2075.32325 1977 2065.16174 1978 2127.95211 1979 2143.07778 1980 2196.9538 1981 2355.56199 1982 2496.50336 1983 2477.99047 1984 2622.88168 1985 2561.50892 1986 2608.80548 1987 2646.54417 1988 2696.95579 1989 2528.56168 1990 2421.5866 1991 2471.0215 1992 2250.64908 1993 2355.77096 1994 2381.63553 1995 2460.15855 1996 2466.51003 1997 2489.16914 1998 2433.053 1999 2424.93337 2000 2384.54809 2001 2417.85259 2002 2339.76307 2003 2469.20555 2004 2662.48346 2005 2626.98137 2006 2579.24562 2007 2732.91794 2008 2913.13007 2009 2824.46436 2010 2748.3635 2011 2703.17889 2012 2628.44834 2013 2598.95973 2014 2695.73376