Year Percent 2003-01-01 66.300 2004-01-01 67.025 2005-01-01 73.350 2006-01-01 74.125 2007-01-01 74.500 2008-01-01 73.500 2009-01-01 66.500 2010-01-01 65.350 2011-01-01 66.550 2012-01-01 68.375 2013-01-01 75.125 2014-01-01 73.600 2015-01-01 76.500 2016-01-01 78.150 2017-01-01 76.525