Year	Ratio
1971-01-01	0.942089974880219
1972-01-01	0.946189999580383
1973-01-01	0.947709977626801
1974-01-01	0.947539985179901
1975-01-01	0.874059975147247
1976-01-01	0.936249971389771
1977-01-01	0.931760013103485
1978-01-01	0.942179977893829
1979-01-01	0.940450012683868
1982-01-01	0.953509986400604
1985-01-01	0.976230025291443
1986-01-01	0.969049990177155
1987-01-01	0.983940005302429
1988-01-01	0.986119985580444
1989-01-01	1.005529999732970
1990-01-01	1.097550034523010
1991-01-01	1.019359946250920
1992-01-01	1.008829951286320
1993-01-01	0.976729989051819
1994-01-01	1.037420034408570
2001-01-01	1.003129959106450
2002-01-01	0.986479997634888
2005-01-01	0.980350017547607
2006-01-01	0.988479971885681
2007-01-01	0.977069973945618
2008-01-01	0.996990025043488
2009-01-01	0.997870028018951
2010-01-01	0.993629992008209
2011-01-01	0.997990012168884
2012-01-01	0.994180023670197
2013-01-01	1.012099981307980
2014-01-01	1.014420032501220
2015-01-01	1.007689952850340
2016-01-01	1.000570058822630