Year Percent 2000 13.1305 2001 20.3232 2002 16.4972 2003 15.6013 2004 18.8104 2005 16.214 2006 16.4084 2007 14.9816 2008 13.1038 2009 16.1871 2010 14.4394 2011 13.7331 2012 13.525 2013 15.1519 2014 13.6858 2015 13.858 2016 11.1598 2017 12.2478