Year Percent 1996 0.25904 1997 0.32938 2001 1.3166 2002 4.05632 2003 3.73855 2004 4.01896 2005 8.4037 2006 5.65515 2007 10.6452 2008 3.73896 2009 2.50689 2010 2.34968 2011 2.22634 2012 2.74193 2013 3.75753 2014 3.72964 2015 3.83071 2016 4.37655