Year Percent 2005-01-01 11.613600000000000 2006-01-01 11.036900000000000 2007-01-01 10.380999999999998 2008-01-01 10.283200000000000 2009-01-01 7.741660000000000 2010-01-01 8.212120000000000 2011-01-01 8.161120000000000 2012-01-01 7.817470000000000 2013-01-01 7.908010000000001 2014-01-01 7.669310000000000 2015-01-01 8.101820000000000 2016-01-01 7.953630000000000 2017-01-01 7.909700000000000