Year Percent 2011-01-01 7.9648699999999995 2012-01-01 7.9648699999999995 2013-01-01 7.9648699999999995 2014-01-01 4.1905100000000000 2015-01-01 4.1905100000000000 2016-01-01 4.1905100000000000 2017-01-01 2.7841700000000000