Year	Ratio
1971-01-01	0.988640010356903
1972-01-01	0.991699993610382
1973-01-01	0.994480013847351
1974-01-01	0.998229980468750
1975-01-01	0.993979990482330
1976-01-01	0.992839992046356
1977-01-01	0.993749976158142
1978-01-01	0.992730021476746
1979-01-01	0.994080007076263
1980-01-01	0.994130015373230
1981-01-01	0.993900001049042
1982-01-01	0.992229998111725
1983-01-01	0.994000017642975
1984-01-01	0.994009971618652
1985-01-01	0.994419991970062
1986-01-01	0.981679975986481
1987-01-01	0.985800027847290
1988-01-01	0.985000014305115
1989-01-01	0.989719986915588
1990-01-01	0.996230006217957
1991-01-01	0.997749984264374
1992-01-01	0.994369983673096
1993-01-01	0.994989991188049
1994-01-01	0.994059979915619
1995-01-01	0.991079986095428
1996-01-01	0.992959976196289
1997-01-01	0.991559982299805
1998-01-01	0.991469979286194
1999-01-01	0.990920007228851
2000-01-01	0.989709973335266
2001-01-01	0.989740014076233
2002-01-01	0.990329980850220
2003-01-01	0.994180023670197
2004-01-01	1.001549959182740
2005-01-01	0.998470008373261
2006-01-01	0.991729974746704
2007-01-01	0.987649977207184
2008-01-01	0.983349978923798
2009-01-01	0.988780021667480
2010-01-01	0.987010002136230
2011-01-01	0.990520000457764
2012-01-01	0.991869986057281
2013-01-01	0.989499986171722
2014-01-01	0.994210004806519
2015-01-01	0.991469979286194
2016-01-01	0.994920015335083