Year Percent 2005-01-01 1.44893548896259 2006-01-01 1.47932546779420 2007-01-01 1.52411977106765 2008-01-01 1.63998048364717 2009-01-01 2.28848690009894 2010-01-01 2.27146533714303 2011-01-01 2.23262720022000 2012-01-01 2.15451043494300 2013-01-01 2.16206874633367 2014-01-01 2.09563895169305 2015-01-01 1.89552524435524 2016-01-01 1.70551488403483 2017-01-01 1.50866702376497