Year Ratio 2003-01-01 0.380970001220703 2004-01-01 0.370900005102158 2006-01-01 0.434439986944199 2007-01-01 0.467990010976791 2008-01-01 0.516629993915558 2009-01-01 0.493380010128021 2010-01-01 0.616930007934570 2011-01-01 0.531679987907410 2012-01-01 0.553080022335052 2014-01-01 0.475100010633469 2015-01-01 0.488099992275238 2016-01-01 0.546019971370697