Year	Ratio
1971-01-01	0.656859993934631
1972-01-01	0.655319988727570
1973-01-01	0.654049992561340
1974-01-01	0.657069981098175
1975-01-01	0.657710015773773
1976-01-01	0.666320025920868
1977-01-01	0.674340009689331
1978-01-01	0.685169994831085
1979-01-01	0.696539998054504
1980-01-01	0.705110013484955
1981-01-01	0.717920005321503
1982-01-01	0.729960024356842
1983-01-01	0.746510028839111
1984-01-01	0.768109977245331
1985-01-01	0.788460016250610
1986-01-01	0.806119978427887
1987-01-01	0.819050014019012
1988-01-01	0.789149999618530
1989-01-01	0.835550010204315
1990-01-01	0.850049972534180
1991-01-01	0.841210007667542
1992-01-01	0.861760020256042
1993-01-01	0.868680000305176
1994-01-01	0.854730010032654
1995-01-01	0.888180017471313
1996-01-01	0.762969970703125
1997-01-01	0.878430008888245
1999-01-01	0.923250019550323
2000-01-01	0.931100010871887
2001-01-01	0.940599977970123
2002-01-01	0.948339998722076
2003-01-01	0.957360029220581
2004-01-01	0.967779994010925
2005-01-01	0.947329998016357
2006-01-01	0.950420022010803
2007-01-01	0.957989990711212
2009-01-01	0.967360019683838
2010-01-01	0.971019983291626
2011-01-01	0.954859972000122
2012-01-01	0.986660003662109
2013-01-01	0.991280019283295
2014-01-01	0.997030019760132
2016-01-01	1.000779986381530