Year	Ratio
1973-01-01	0.55598
1974-01-01	0.56787
1975-01-01	0.58407
1976-01-01	0.58945
1977-01-01	0.60471
1978-01-01	0.59224
1979-01-01	0.58688
1980-01-01	0.57959
1981-01-01	0.56586
1982-01-01	0.58486
1983-01-01	0.59642
1984-01-01	0.60800
1985-01-01	0.61155
1986-01-01	0.59679
1987-01-01	0.60211
1988-01-01	0.61854
1989-01-01	0.63941
1990-01-01	0.65548
1991-01-01	0.68300
1992-01-01	0.71331
1993-01-01	0.74609
1994-01-01	0.74932
1995-01-01	0.75285
1996-01-01	0.75364
1997-01-01	0.77926
1998-01-01	0.79746
1999-01-01	0.82820
2000-01-01	0.84061
2001-01-01	0.82828
2002-01-01	0.86009
2003-01-01	0.86797
2004-01-01	0.89588
2005-01-01	0.90504
2006-01-01	0.93991
2007-01-01	0.97659
2008-01-01	0.99412
2009-01-01	1.01435
2010-01-01	1.02995
2011-01-01	1.04486
2012-01-01	1.07575
2013-01-01	1.10175
2014-01-01	1.12836
2015-01-01	1.14462
2016-01-01	1.16050