Year Percent 1994 3.5286 1995 3.92436 1996 3.46738 1997 3.60617 1998 3.7152 1999 4.89795 2000 5.91579 2001 6.4505 2002 6.84589 2003 6.25651 2004 7.07093 2005 6.34741 2006 5.46418 2007 4.58727 2008 3.91492 2009 4.11109 2010 5.25568 2011 4.77534 2012 5.1394 2013 5.18212 2014 4.84003 2015 4.41013 2016 3.49692 2017 2.84571