Year	Ratio
1973-01-01	0.268469989299774
1974-01-01	0.240060001611710
1975-01-01	0.277929991483688
1976-01-01	0.205039992928505
1977-01-01	0.252119988203049
1978-01-01	0.230330005288124
1979-01-01	0.261680006980896
1980-01-01	0.302159994840622
1981-01-01	0.332720011472702
1982-01-01	0.384660005569458
1983-01-01	0.379260003566742
1984-01-01	0.418590009212494
1985-01-01	0.464489996433258
1986-01-01	0.513459980487823
1987-01-01	0.564199984073639
1988-01-01	0.615589976310730
1989-01-01	0.672670006752014
1990-01-01	0.717890024185181
1991-01-01	0.806819975376129
1992-01-01	0.867850005626678
1993-01-01	0.911390006542206
1994-01-01	0.933340013027191
1995-01-01	0.946200013160706
1996-01-01	0.941299974918365
1997-01-01	0.989549994468689
1998-01-01	1.001610040664670
1999-01-01	1.008759975433350
2000-01-01	0.992229998111725
2001-01-01	0.984610021114349
2002-01-01	0.968760013580322
2003-01-01	0.953729987144470
2005-01-01	0.963329970836639
2006-01-01	0.982089996337891
2007-01-01	0.989910006523132
2008-01-01	0.981589972972870
2009-01-01	0.953679978847504
2011-01-01	0.960189998149872
2012-01-01	0.985109984874725
2013-01-01	1.014629960060120
2015-01-01	0.980740010738373
2016-01-01	0.941190004348755