Year Percent 2006-01-01 19.7240 2007-01-01 20.1211 2008-01-01 18.0405 2009-01-01 27.8356 2010-01-01 20.4561 2011-01-01 16.0827 2012-01-01 15.6511 2013-01-01 12.5969 2014-01-01 12.5639 2015-01-01 12.3564 2016-01-01 11.8151