Year Percent 2006-01-01 34.5618 2007-01-01 31.5234 2008-01-01 30.7446 2009-01-01 30.8481 2010-01-01 30.1497 2011-01-01 28.8478 2012-01-01 26.6411 2013-01-01 33.6150 2014-01-01 37.0279 2015-01-01 34.7166 2016-01-01 34.6305