Year Percent 2006-01-01 69.9 2007-01-01 69.9 2008-01-01 69.9 2009-01-01 69.9 2010-01-01 66.8 2011-01-01 66.8 2012-01-01 66.8 2013-01-01 66.8 2014-01-01 66.8 2015-01-01 66.8 2016-01-01 66.8 2017-01-01 77.8