Year Percent 2006-01-01 40.8004 2007-01-01 51.9562 2008-01-01 44.0835 2009-01-01 58.5172 2010-01-01 50.6705 2011-01-01 56.3304 2012-01-01 52.2257 2013-01-01 54.1429 2014-01-01 58.8682 2015-01-01 44.5849 2016-01-01 61.9724