Year Percent 2009-01-01 6.800000000000000 2010-01-01 5.204160000000000 2011-01-01 3.918600000000000 2012-01-01 5.436820000000000 2013-01-01 6.952500000000000 2014-01-01 6.752160000000001 2015-01-01 6.594170000000000 2016-01-01 7.186750000000000