Year	Ratio
2001-01-01	0.845809996128082
2002-01-01	0.844139993190765
2003-01-01	0.858399987220764
2004-01-01	0.855769991874695
2005-01-01	0.877460002899170
2006-01-01	0.865869998931885
2007-01-01	0.841669976711273
2008-01-01	0.869910001754761
2009-01-01	0.891919970512390
2010-01-01	0.898710012435913
2011-01-01	0.887120008468628
2012-01-01	0.891900002956390
2013-01-01	0.899879992008209
2015-01-01	0.916649997234344