Year	Ratio
1999-01-01	0.436800003051758
2000-01-01	0.451189994812012
2001-01-01	0.410320013761520
2002-01-01	0.429729998111725
2003-01-01	0.441599994897842
2004-01-01	0.454180002212524
2005-01-01	0.477649986743927
2006-01-01	0.488449990749359
2007-01-01	0.495950013399124
2008-01-01	0.511300027370453
2009-01-01	0.528909981250763
2010-01-01	0.528949975967407
2011-01-01	0.524879992008209
2012-01-01	0.524049997329712
2013-01-01	0.560810029506683
2014-01-01	0.605279982089996
2015-01-01	0.668290019035339
2016-01-01	0.714470028877258
2017-01-01	0.750339984893799