Year	Ratio
1999-01-01	0.856019973754883
2000-01-01	0.855620026588440
2001-01-01	0.828939974308014
2002-01-01	0.820060014724731
2003-01-01	0.828450024127960
2004-01-01	0.837819993495941
2005-01-01	0.831570029258728
2006-01-01	0.829450011253357
2007-01-01	0.843029975891113
2008-01-01	0.875039994716644
2009-01-01	0.888580024242401
2010-01-01	0.873300015926361
2011-01-01	0.881229996681213
2012-01-01	0.898190021514893
2013-01-01	0.898970007896423