Year Measure 1971 217.47241 1972 234.53774 1973 213.61576 1974 234.03676 1975 249.87479 1976 284.50794 1977 303.54668 1978 305.57589 1979 328.21066 1980 342.29587 1981 389.01299 1982 415.34228 1983 449.10277 1984 485.00106 1985 511.01425 1986 510.65299 1987 529.15055 1988 527.13352 1989 547.43514 1990 561.74281 1991 549.23657 1992 551.54189 1993 560.34878 1994 528.55366 1995 551.33677 1996 574.19542 1997 587.00873 1998 617.5315 1999 619.83482 2000 580.60483 2001 639.94191 2002 647.73773 2003 659.77856 2004 699.93011 2005 800.69828 2006 831.09115 2007 874.79545 2008 892.82105 2009 896.78559 2010 862.51073 2011 886.31327 2012 891.24155 2013 835.37355 2014 814.98806