Year Percent 2000 4.03638 2001 2.84637 2002 2.95016 2003 2.67412 2004 2.35935 2005 2.36979 2006 2.33651 2007 2.28088 2008 6.72509 2009 6.6171 2010 7.05469 2011 7.35287 2012 7.24719 2013 7.15144 2014 7.34643 2015 7.62992 2016 8.17521 2017 8.51139