Year Percent 2008-01-01 5.42028 2009-01-01 6.36260 2010-01-01 7.69188 2011-01-01 6.59691 2012-01-01 12.70570 2013-01-01 13.03230 2014-01-01 12.88050 2015-01-01 13.31760 2016-01-01 18.53170