Year	Ratio
1970-01-01	0.99498
1971-01-01	0.99497
1972-01-01	0.99631
1973-01-01	1.00550
1974-01-01	0.99499
1975-01-01	0.99627
1976-01-01	1.00634
1977-01-01	0.99537
1978-01-01	0.99555
1979-01-01	0.99348
1980-01-01	0.99482
1981-01-01	0.99476
1982-01-01	0.99520
1983-01-01	0.99516
1984-01-01	0.99359
1985-01-01	0.99256
1986-01-01	0.99169
1987-01-01	0.99360
1988-01-01	0.99088
1989-01-01	0.99346
1990-01-01	0.99493
1991-01-01	0.99679
1992-01-01	0.99728
1993-01-01	0.99574
1994-01-01	0.99398
1995-01-01	0.99071
1996-01-01	0.99025
1997-01-01	0.99064
1998-01-01	0.98986
1999-01-01	0.99062
2000-01-01	0.99231
2001-01-01	0.99280
2002-01-01	0.99118
2003-01-01	0.99179
2004-01-01	0.99163
2005-01-01	0.99049
2006-01-01	0.99121
2007-01-01	0.99140
2008-01-01	0.99012
2009-01-01	0.99186
2010-01-01	0.99249
2011-01-01	0.99439
2012-01-01	0.99612
2013-01-01	0.99804
2014-01-01	0.99817
2015-01-01	0.99885
2016-01-01	0.99962