Year	Ratio
1971-01-01	0.782029986381531
1972-01-01	0.861710011959076
1973-01-01	0.842480003833771
1974-01-01	0.832430005073547
1975-01-01	0.824930012226105
1976-01-01	0.841019988059998
1977-01-01	0.853259980678558
1978-01-01	0.856760025024414
1979-01-01	0.892560005187988
1980-01-01	0.937470018863678
1981-01-01	0.964420020580292
1982-01-01	0.997810006141663
1983-01-01	1.001109957695010
1984-01-01	0.976040005683899
1985-01-01	0.936869978904724
1986-01-01	0.910340011119843
1987-01-01	0.907790005207062
1988-01-01	0.930100023746490
1989-01-01	0.953760027885437
1990-01-01	0.972800016403198
1991-01-01	0.947740018367767
1992-01-01	1.001670002937320
1993-01-01	1.025959968566890
1994-01-01	1.011719942092900
1995-01-01	1.012740015983580
1996-01-01	0.911010026931763
1997-01-01	0.886720001697540
1998-01-01	0.898899972438812
1999-01-01	0.942709982395172
2000-01-01	1.022709965705870
2001-01-01	1.090600013732910
2002-01-01	1.110270023345950
2003-01-01	1.126430034637450
2004-01-01	1.091879963874820
2005-01-01	1.036249995231630
2006-01-01	0.997640013694763
2007-01-01	0.977569997310638
2008-01-01	0.976960003376007
2009-01-01	0.980350017547607
2010-01-01	0.985099971294403
2011-01-01	0.997539997100830
2012-01-01	1.019150018692020
2013-01-01	1.034160017967220
2014-01-01	1.033210039138790
2015-01-01	1.040300011634830
2016-01-01	1.039420008659360