Year Percent 2005-01-01 22.5883 2006-01-01 19.6107 2007-01-01 18.4641 2008-01-01 17.4353 2009-01-01 17.9332 2010-01-01 17.5410 2011-01-01 17.0944 2012-01-01 15.7424 2013-01-01 14.1586 2014-01-01 13.5967 2015-01-01 13.5741 2016-01-01 13.6672