Year Percent 2006-01-01 42.750 2007-01-01 42.725 2008-01-01 43.025 2009-01-01 42.550 2010-01-01 44.500 2011-01-01 46.525 2012-01-01 46.950 2013-01-01 47.550 2014-01-01 47.350 2015-01-01 47.900 2016-01-01 48.275 2017-01-01 49.000