Year Ratio 1976-01-01 0.937569975852966 1977-01-01 0.926010012626648 1978-01-01 0.938139975070953 1979-01-01 0.960659980773926 1980-01-01 0.973930001258850 1981-01-01 0.950720012187958 1982-01-01 0.737569987773895 1984-01-01 0.976549983024597 1985-01-01 0.861850023269653 1986-01-01 0.733269989490509 1987-01-01 0.991010010242462 1988-01-01 0.973779976367950 1989-01-01 0.974210023880005 1990-01-01 0.944949984550476 1991-01-01 0.991829991340637 1992-01-01 0.967279970645905 1993-01-01 0.980750024318695 1994-01-01 0.986689984798431 1995-01-01 1.013730049133300 1998-01-01 0.979849994182587 2000-01-01 1.035599946975710 2001-01-01 1.091140031814580 2002-01-01 1.054100036621090 2003-01-01 1.022179961204530 2004-01-01 1.050469994544980 2005-01-01 1.018829941749570 2007-01-01 0.999400019645691 2008-01-01 1.014170050621030 2009-01-01 1.016399979591370 2010-01-01 1.001119971275330 2011-01-01 1.019680023193360 2012-01-01 1.012459993362430 2013-01-01 1.032950043678280 2014-01-01 1.018319964408870 2015-01-01 1.020720005035400