Year Percent 2004-01-01 5.166890000000000 2005-01-01 9.906150000000000 2006-01-01 21.223600000000000 2007-01-01 13.742100000000000 2008-01-01 18.916000000000000 2009-01-01 21.007100000000000 2010-01-01 16.022000000000002 2011-01-01 11.418700000000000 2012-01-01 10.897100000000000 2013-01-01 24.595700000000000 2014-01-01 33.623300000000000 2015-01-01 14.390300000000000 2016-01-01 10.111900000000000