Year Percent 2005-01-01 49.900 2006-01-01 50.800 2007-01-01 52.275 2008-01-01 53.225 2009-01-01 53.450 2010-01-01 53.675 2011-01-01 54.350 2012-01-01 55.600 2013-01-01 56.675 2014-01-01 57.975 2015-01-01 59.500 2016-01-01 61.550 2017-01-01 63.225