Year Percent 2009-01-01 5.7986699999999995 2010-01-01 5.4143700000000000 2011-01-01 5.8909699999999990 2012-01-01 7.0347100000000005 2013-01-01 8.0038500000000000 2014-01-01 8.5455100000000000 2015-01-01 10.0577000000000000 2016-01-01 10.0540000000000000