Year Percent 2005-01-01 47.575 2006-01-01 46.850 2007-01-01 46.000 2008-01-01 45.275 2009-01-01 45.700 2010-01-01 46.275 2011-01-01 45.225 2012-01-01 46.775 2013-01-01 47.125 2014-01-01 47.975 2015-01-01 49.550 2016-01-01 49.075 2017-01-01 48.725