Year Ratio 1971-01-01 0.989520013332367 1972-01-01 0.992460012435913 1973-01-01 0.991379976272583 1974-01-01 0.993629992008209 1975-01-01 0.987810015678406 1976-01-01 0.999270021915436 1977-01-01 0.997619986534119 1978-01-01 0.998709976673126 1979-01-01 0.999509990215302 1980-01-01 1.000139951705930 1981-01-01 1.001839995384220 1982-01-01 0.984660029411316 1983-01-01 0.975679993629456 1984-01-01 0.973950028419495 1985-01-01 0.975899994373322 1986-01-01 0.977980017662048 1987-01-01 0.980579972267151 1988-01-01 0.981140017509460 1989-01-01 0.969359993934631 1990-01-01 0.992139995098114 1991-01-01 0.984279990196228 1992-01-01 0.985199987888336 1993-01-01 0.986270010471344 1994-01-01 0.985279977321625 1995-01-01 0.986339986324310 1996-01-01 0.985920011997223 1998-01-01 0.999100029468536 1999-01-01 1.001420021057130 2000-01-01 1.001579999923710 2004-01-01 0.991050004959106 2005-01-01 0.991590023040771 2006-01-01 0.992799997329712 2007-01-01 0.995199978351593 2008-01-01 0.998099982738495 2009-01-01 1.001360058784480 2010-01-01 1.004979968070980 2011-01-01 1.006839990615840 2012-01-01 1.010390043258670 2013-01-01 1.010810017585750 2014-01-01 1.011719942092900 2015-01-01 1.007889986038210 2016-01-01 1.000740051269530