Year Percent 1991 0.969 1992 0.975 1993 1.491 1994 1.644 1995 3.835 1996 1.407 1997 2.587 1998 0.648 1999 0.329 2000 0.944 2001 0.804 2002 0.6459 2003 0.9988 2004 1.2877 2005 0.9759 2006 1.0806 2007 0.9538 2008 0.9968 2009 1.6262 2010 1.6313 2011 1.4935 2012 1.848 2013 1.4819 2014 1.4095 2015 1.4246 2016 1.2247 2017 1.1969