Year	Ratio
1970-01-01	1.13591003417969
1971-01-01	1.12264001369476
1972-01-01	1.10175001621246
1973-01-01	1.11355996131897
1974-01-01	1.11634004116058
1975-01-01	1.13046002388000
1976-01-01	1.13021004199982
1977-01-01	1.14021003246307
1978-01-01	1.14362001419067
1979-01-01	1.13285005092621
1980-01-01	1.13937997817993
1981-01-01	1.14859998226166
1982-01-01	1.10717999935150
1983-01-01	1.07053995132446
1984-01-01	1.10037994384766
1985-01-01	1.11533999443054
1986-01-01	1.10020995140076
1987-01-01	1.07889997959137
1988-01-01	1.08455002307892
1996-01-01	1.10652005672455
1997-01-01	1.09435999393463
1998-01-01	1.05931997299194
1999-01-01	1.07411003112793
2000-01-01	1.06289994716644
2001-01-01	1.06360995769501
2002-01-01	1.06182003021240
2003-01-01	1.06907999515533
2004-01-01	1.08380997180939
2005-01-01	1.09599995613098
2006-01-01	1.10925996303558
2007-01-01	1.11904001235962
2008-01-01	1.12706005573273
2009-01-01	1.11741995811462
2010-01-01	1.09786999225616
2011-01-01	1.10412001609802
2012-01-01	1.08928000926971
2013-01-01	1.07588005065918
2014-01-01	1.06717002391815
2015-01-01	1.05938994884491