Year Percent 1996 5.08 1997 7.47 1998 6.22 1999 6.21 2000 4.8 2001 5.25 2002 4.23 2003 4.18 2004 4.62 2005 2.1 2006 1.58 2007 1.81 2008 1.17 2009 1.4 2010 1.42 2011 1.1 2012 0.75 2013 0.63 2014 0.57 2015 0.62 2016 0.66 2017 0.42