Year Percent 1995 0.26857 1996 0 1997 3.06444 1998 0.61802 1999 0.60839 2000 0.79173 2001 1.44647 2002 3.04424 2003 6.92344 2004 3.85524 2005 6.0073 2006 13.9039 2007 10.98033 2008 8.23322 2009 6.87261 2010 4.29122 2011 10.60952 2012 3.13213 2013 4.52486 2014 4.5227 2015 6.3109 2016 6.14816 2017 6.94835