Year Percent 2011-01-01 2.8194200000000000 2012-01-01 2.8194200000000000 2013-01-01 2.8194200000000000 2014-01-01 3.5663900000000000 2015-01-01 3.5663900000000000 2016-01-01 3.5663900000000000 2017-01-01 3.6678900000000003