Year Percent 2006-01-01 9.175 2007-01-01 9.225 2008-01-01 10.075 2009-01-01 12.675 2010-01-01 11.450 2011-01-01 10.125 2012-01-01 9.450 2013-01-01 10.600 2014-01-01 11.825 2015-01-01 12.650 2016-01-01 13.625 2017-01-01 13.950