Year Measure 1971 434.19563 1972 435.42479 1973 439.02134 1974 449.42155 1975 448.75561 1976 460.02072 1977 474.53437 1978 476.3176 1979 467.93727 1980 446.29668 1981 435.02145 1982 414.60181 1983 426.41393 1984 431.88889 1985 433.20026 1986 490.73768 1987 512.0116 1988 513.96756 1989 561.16184 1990 629.38207 1991 634.42172 1992 657.78682 1993 678.84149 1994 657.62379 1995 697.00398 1996 702.2344 1997 712.57198 1998 750.44316 1999 775.37445 2000 851.22166 2001 886.76379 2002 873.1958 2003 909.06319 2004 919.7979 2005 945.72377 2006 1006.50164 2007 1007.57484 2008 1027.17421 2009 999.48694 2010 1053.4525 2011 1053.50989 2012 1067.78025 2013 1094.72587 2014 1111.42217