Year	Ratio
1981-01-01	0.987739980220795
1986-01-01	1.005499958992000
1989-01-01	1.065199971199040
1990-01-01	1.026239991188050
1992-01-01	1.018640041351320
1993-01-01	1.013939976692200
1994-01-01	1.023309946060180
1995-01-01	1.014950037002560
1996-01-01	0.976230025291443
1997-01-01	0.958760023117065
1998-01-01	0.948419988155365
1999-01-01	0.991659998893738
2000-01-01	0.986620008945465
2001-01-01	0.980220019817352
2002-01-01	0.982110023498535
2003-01-01	0.989310026168823
2004-01-01	0.993359982967377
2005-01-01	0.984200000762939
2006-01-01	0.985069990158081
2007-01-01	0.988849997520447
2008-01-01	0.991940021514893
2009-01-01	0.997240006923676
2010-01-01	0.991829991340637
2011-01-01	0.991100013256073
2012-01-01	0.987450003623962
2013-01-01	0.988629996776581
2014-01-01	0.990620017051697
2015-01-01	0.992780029773712
2016-01-01	0.989709973335266