Year	Ratio
1991-01-01	0.990750014781952
1992-01-01	0.993359982967377
1993-01-01	0.995739996433258
1994-01-01	0.998149991035461
1995-01-01	0.999180018901825
1996-01-01	1.000319957733150
1997-01-01	1.001399993896480
1998-01-01	0.990239977836609
1999-01-01	0.984489977359772
2000-01-01	0.986720025539398
2001-01-01	0.993510007858276
2002-01-01	0.996159970760345
2003-01-01	0.988399982452393
2004-01-01	0.988929986953735
2005-01-01	0.988640010356903
2006-01-01	0.988979995250702
2007-01-01	0.993969976902008
2008-01-01	0.993160009384155
2009-01-01	0.993390023708344
2010-01-01	0.991209983825684
2011-01-01	0.991289973258972
2012-01-01	0.990239977836609
2013-01-01	0.985750019550323
2014-01-01	0.990819990634918
2015-01-01	0.992330014705658