Year Percent 2011-01-01 6.0963100000000000 2012-01-01 6.0963100000000000 2013-01-01 6.0963100000000000 2014-01-01 7.9496899999999995 2015-01-01 7.9496899999999995 2016-01-01 7.9496899999999995 2017-01-01 5.7035500000000000