Year Percent 2005-01-01 37.575 2006-01-01 40.300 2007-01-01 43.400 2008-01-01 46.000 2009-01-01 48.600 2010-01-01 50.700 2011-01-01 53.225 2012-01-01 54.950 2013-01-01 57.650 2014-01-01 59.975 2015-01-01 61.200 2016-01-01 63.550 2017-01-01 65.375