Year	Ratio
1972-01-01	0.930779993534088
1973-01-01	0.922060012817383
1974-01-01	0.931219995021820
1975-01-01	0.958410024642944
1976-01-01	0.977789998054504
1977-01-01	0.987749993801117
1978-01-01	0.992399990558624
1979-01-01	0.995490014553070
1980-01-01	0.992739975452423
1981-01-01	0.991940021514893
1982-01-01	1.003790020942690
1983-01-01	0.992820024490356
1984-01-01	0.994660019874573
1985-01-01	0.997839987277985
1986-01-01	0.999279975891113
1987-01-01	1.006160020828250
1988-01-01	1.001330018043520
1989-01-01	0.996840000152588
1990-01-01	0.995090007781982
1991-01-01	0.994040012359619
1992-01-01	0.996869981288910
1993-01-01	0.997420012950897
1994-01-01	0.997850000858307
1995-01-01	0.997359991073608
1996-01-01	1.002189993858340
1997-01-01	1.001489996910100
1998-01-01	0.997479975223541
1999-01-01	0.996680021286011
2000-01-01	0.994199991226196
2001-01-01	0.994920015335083
2002-01-01	0.993520021438599
2003-01-01	0.991310000419617
2004-01-01	0.991029977798462
2005-01-01	0.992349982261658
2006-01-01	0.996169984340668
2007-01-01	0.995389997959137
2008-01-01	0.991810023784637
2009-01-01	0.993499994277954
2010-01-01	0.993480026721954
2011-01-01	0.992049992084503
2012-01-01	0.991540014743805
2013-01-01	0.992250025272369
2014-01-01	0.995580017566681
2015-01-01	0.993990004062653
2016-01-01	0.995530009269714