Year Measure 1971 2696.68404 1972 2829.46912 1973 3026.21274 1974 3138.20535 1975 3111.76899 1976 3260.46084 1977 3413.48964 1978 3468.62299 1979 3806.45936 1980 4358.59565 1981 4411.78963 1982 4439.28002 1983 4520.84271 1984 4624.05919 1985 4841.36443 1986 4941.62506 1987 5085.16439 1988 5150.46292 1989 5266.16858 1990 5542.1709 1991 5115.12279 1992 4699.13757 1993 4570.44244 1994 4582.58196 1995 4925.96138 1996 5150.40772 1997 5068.08939 1998 4682.29758 1999 5028.70634 2000 4955.9079 2001 5027.45281 2002 5051.59839 2003 5021.79822 2004 5097.83556 2005 4932.80328 2006 5153.12148 2007 5272.37078 2008 5294.4351 2009 4954.13825 2010 5201.4049 2011 5347.52622 2012 5137.78902 2013 5202.46729 2014 5137.07384