Year Measure 1990 2857.56453 1991 2778.95039 1992 2584.33517 1993 2715.38991 1994 2827.91716 1995 3049.38659 1996 3180.20615 1997 3310.40063 1998 3253.80886 1999 3242.48618 2000 3224.3795 2001 3381.11201 2002 3424.45288 2003 3463.52493 2004 3571.19487 2005 3645.83744 2006 3648.98289 2007 3632.56533 2008 3836.62179 2009 3496.22954 2010 3579.07246 2011 3567.98304 2012 3424.04014 2013 3330.99008 2014 3236.23604 2015 3174.87258