Year Percent 2004-01-01 1.84 2005-01-01 1.68 2006-01-01 2.05 2007-01-01 2.20 2008-01-01 1.81 2009-01-01 2.32 2010-01-01 2.18 2011-01-01 2.09 2012-01-01 2.00 2013-01-01 2.35 2014-01-01 2.44 2015-01-01 2.90 2016-01-01 1.29