Year Percent 2007-01-01 12.65960 2008-01-01 9.65698 2009-01-01 13.70500 2010-01-01 14.91550 2011-01-01 12.14230 2012-01-01 12.52460 2013-01-01 13.25370 2014-01-01 14.67920 2015-01-01 16.61540 2016-01-01 17.23170