Year Percent 2008-01-01 39.1060 2009-01-01 41.4869 2010-01-01 38.2187 2011-01-01 41.8120 2012-01-01 43.2078 2013-01-01 45.6190 2014-01-01 49.8169 2015-01-01 45.4662 2016-01-01 42.6622