Year Percent 1996 9.66454 1997 9.34427 1998 11.97796 1999 12.33684 2000 16.06693 2001 14.03756 2002 19.15674 2003 18.97823 2004 12.92453 2005 8.43751 2006 7.77732 2007 6.87841 2008 6.47485 2009 9.22873 2010 9.06634 2011 7.97209 2012 8.37538 2013 10.00599 2014 11.45167 2015 13.76032 2016 10.71925