Year Percent 2011-01-01 15.972200000000000 2012-01-01 15.972200000000000 2013-01-01 15.972200000000000 2014-01-01 26.523300000000000 2015-01-01 26.523300000000000 2016-01-01 26.523300000000000 2017-01-01 19.480999999999998