Year Measure 1990 4380.90097 1991 4426.03492 1992 3912.88175 1993 3450.23928 1994 3068.34849 1995 2789.97449 1996 2806.49606 1997 2953.04932 1998 3016.28762 1999 3005.36426 2000 2996.30948 2001 3009.40248 2002 3000.74563 2003 3063.05694 2004 3174.05309 2005 3245.37209 2006 3365.98187 2007 3393.90854 2008 3481.74352 2009 3298.70361 2010 3563.63777 2011 3628.45729 2012 3697.39748 2013 3648.32146 2014 3679.97884