Year Percent 1993 2.10218 1994 1.74965 1995 1.78085 1996 1.46277 1997 1.30827 1998 1.25423 1999 1.15057 2000 1.23031 2001 1.15773 2002 1.07602 2003 1.22464 2004 0.52829 2005 0.54143 2006 0.50078 2007 0.52038 2008 0.51805 2009 0.50499 2010 0.54433 2011 0.51218 2012 0.50912 2013 0.45447 2014 0.46792 2015 0.4718 2016 0.43329 2017 0.42703 2018 0.41004 2019 0.46113 2020 0.5023