Year Percent 2006-01-01 0.800 2007-01-01 1.050 2008-01-01 1.000 2009-01-01 1.475 2010-01-01 1.200 2011-01-01 1.350 2012-01-01 1.600 2013-01-01 2.200 2014-01-01 2.350 2015-01-01 3.325 2016-01-01 2.975 2017-01-01 3.100