Year	Ratio
1971-01-01	0.940060019493103
1972-01-01	0.910300016403198
1974-01-01	0.941980004310608
1975-01-01	0.926649987697601
1976-01-01	0.927869975566864
1977-01-01	0.958289980888367
1978-01-01	0.946680009365082
1979-01-01	0.973190009593964
1980-01-01	0.986440002918243
1981-01-01	0.977419972419739
1982-01-01	0.976310014724731
1983-01-01	0.960039973258972
1984-01-01	0.962130010128021
1985-01-01	0.972649991512299
1986-01-01	0.973439991474152
1987-01-01	0.971469998359680
1988-01-01	0.968739986419678
1989-01-01	0.968559980392456
1990-01-01	0.961399972438812
1991-01-01	0.968750000000000
1992-01-01	0.969799995422363
1993-01-01	0.970939993858337
1994-01-01	0.967109978199005
1995-01-01	0.971340000629425
1996-01-01	0.971390008926392
1997-01-01	0.974449992179871
1998-01-01	0.978309988975525
1999-01-01	0.982140004634857
2000-01-01	0.985409975051880
2001-01-01	0.986509978771210
2002-01-01	0.986750006675720
2003-01-01	0.985859990119934
2004-01-01	0.985040009021759
2005-01-01	0.981620013713837
2006-01-01	0.979799985885620
2007-01-01	0.979659974575043
2008-01-01	0.981050014495850
2009-01-01	0.985059976577759
2010-01-01	0.991219997406006
2011-01-01	0.997300028800964
2012-01-01	1.003090023994450
2013-01-01	1.005280017852780
2014-01-01	1.006500005722050
2015-01-01	1.006479978561400
2016-01-01	1.005550026893620