Year Measure 1971 125.22024 1972 138.90384 1973 152.14821 1974 157.7198 1975 163.16835 1976 178.68563 1977 192.30587 1978 205.85149 1979 222.27513 1980 236.51529 1981 248.34726 1982 261.79034 1983 280.04735 1984 282.51702 1985 294.04488 1986 306.63742 1987 310.54016 1988 340.08268 1989 334.70931 1990 358.13141 1991 370.40893 1992 400.8686 1993 400.83976 1994 420.06899 1995 429.83935 1996 432.58336 1997 450.01238 1998 478.7533 1999 452.39668 2000 489.08788 2001 523.92187 2002 534.96216 2003 580.45291 2004 610.982 2005 633.10362 2006 686.73305 2007 715.8485 2008 732.12983 2009 744.29749 2010 774.36839 2011 823.88831 2012 874.42805 2013 878.58693 2014 901.12845