Year Measure 1971 119.36725 1972 137.50581 1973 144.97431 1974 122.35378 1975 161.80355 1976 192.90176 1977 203.67996 1978 208.25203 1979 214.603 1980 251.80344 1981 211.88007 1982 184.98151 1983 159.54182 1984 164.2443 1985 172.93563 1986 144.21817 1987 165.06334 1988 162.84849 1989 186.50975 1990 200.45741 1991 206.46887 1992 256.47512 1993 243.09034 1994 266.40984 1995 295.62408 1996 259.23589 1997 240.54813 1998 314.63598 1999 363.12692 2000 330.45103 2001 357.98904 2002 363.01541 2003 450.78276 2004 482.5378 2005 480.6801 2006 533.02946 2007 543.4923 2008 530.54447 2009 537.78207 2010 541.95311 2011 534.5537 2012 532.64162 2013 558.40475 2014 577.88589