Year Percent 2011-01-01 8.259139999999999 2012-01-01 8.259139999999999 2013-01-01 8.259139999999999 2014-01-01 9.476100000000000 2015-01-01 9.476100000000000 2016-01-01 9.476100000000000 2017-01-01 8.934740000000000