Year Percent 2011-01-01 3.8006599999999997 2012-01-01 3.8006599999999997 2013-01-01 3.8006599999999997 2014-01-01 4.0760800000000000 2015-01-01 4.0760800000000000 2016-01-01 4.0760800000000000 2017-01-01 7.1978700000000000