Year Percent 2000 16.5663 2001 20.8641 2002 18.7763 2003 14.2029 2004 12.4001 2005 10.2974 2006 8.6437 2007 6.5158 2008 5.4793 2009 6.9848 2010 10.8592 2011 12.2629 2012 13.5221 2013 13.9015 2014 12.3122 2015 9.7772 2016 8.0995 2017 6.354