Year Measure 1971 131.18529 1972 153.6242 1973 173.72301 1974 189.04318 1975 214.25961 1976 255.18037 1977 222.8722 1978 256.86993 1979 326.13588 1980 366.40496 1981 421.34038 1982 497.71108 1983 623.81208 1984 705.2871 1985 745.86022 1986 778.06927 1987 854.56232 1988 854.68194 1989 863.02803 1990 935.24036 1991 902.37391 1992 1000.20211 1993 1024.2441 1994 1055.51629 1995 1112.6409 1996 1158.09331 1997 1163.84297 1998 1226.88879 1999 1254.46195 2000 1294.49965 2001 1330.1288 2002 1409.55403 2003 1452.16383 2004 1564.42081 2005 1592.54869 2006 1695.08034 2007 1802.62485 2008 1866.61514 2009 1831.37188 2010 1865.67424 2011 1868.13287 2012 1941.17714 2013 1877.58574 2014 1888.11695