Year Percent 1992 2.51495 1993 2.67535 1994 2.29731 1995 1.73979 1996 1.62558 1997 1.31332 1998 1.10002 1999 1.05295 2000 0.90647 2001 0.84212 2002 0.75098 2003 1.15586 2004 1.2527 2005 1.02837 2006 0.71596 2007 0.58492 2008 0.40396 2009 0.82157 2010 1.52079 2011 1.67052 2012 1.74492 2013 1.50327 2014 1.3789 2015 1.35597 2016 1.25274 2017 1.13964