Year Ratio 1971-01-01 0.851189970970154 1972-01-01 0.860700011253357 1973-01-01 0.879459977149963 1974-01-01 0.903479993343353 1975-01-01 0.929679989814758 1976-01-01 0.930490016937256 1977-01-01 0.931159973144531 1978-01-01 0.935949981212616 1979-01-01 1.024430036544800 1980-01-01 0.987479984760284 1981-01-01 0.998520016670227 1982-01-01 0.999979972839355 1983-01-01 1.037150025367740 1984-01-01 1.032410025596620 1985-01-01 1.021999955177310 1986-01-01 1.038920044898990 1987-01-01 1.039579987525940 1988-01-01 1.043149948120120 1993-01-01 1.019729971885680 1996-01-01 1.045130014419560 1998-01-01 1.041610002517700 1999-01-01 1.026649951934810 2000-01-01 1.016739964485170 2001-01-01 1.020740032196040 2002-01-01 1.006989955902100 2003-01-01 1.017199993133540 2004-01-01 1.002580046653750 2005-01-01 1.010879993438720 2006-01-01 1.015730023384090 2007-01-01 1.012549996376040 2010-01-01 1.050999999046330 2011-01-01 1.042549967765810 2012-01-01 1.042299985885620 2013-01-01 1.046460032463070 2014-01-01 1.040380001068120 2015-01-01 1.039019942283630 2016-01-01 1.036700010299680 2017-01-01 1.029010057449340