Year Percent 1993 0.7353 1994 0.83876 1995 0.80566 1996 0.63914 1997 0.58212 1998 0.58785 1999 0.75094 2000 0.88171 2001 1.04154 2002 1.54221 2003 1.61002 2004 1.59566 2005 1.61062 2006 1.71502 2007 1.55807 2008 1.63441 2009 1.39006 2010 1.09266 2011 1.04272 2012 0.90927 2013 0.93739 2014 0.94376 2015 1.05024 2016 1.4795 2017 1.72165