Year Percent 2010-01-01 4.48798272270371 2011-01-01 4.07542638517688 2012-01-01 4.27456283553637 2013-01-01 4.60117932668551 2014-01-01 4.69058642155142 2015-01-01 4.70328686415655 2016-01-01 4.84196345414654 2017-01-01 4.57117776328624