Year Percent 2009-01-01 17.4139000000000000 2010-01-01 14.6323000000000000 2011-01-01 12.7113000000000000 2012-01-01 6.6329899999999995 2013-01-01 7.2321200000000000 2014-01-01 5.9725900000000000 2015-01-01 6.7295700000000000 2016-01-01 5.1371199999999995