Year Ratio 1971-01-01 0.722100019454956 1972-01-01 0.730419993400574 1973-01-01 0.738059997558594 1974-01-01 0.740740001201630 1975-01-01 0.752420008182526 1976-01-01 0.768090009689331 1977-01-01 0.790679991245270 1978-01-01 0.810989975929260 1979-01-01 0.839550018310547 1980-01-01 0.859769999980927 1981-01-01 0.888310015201569 1982-01-01 0.875549972057343 1983-01-01 0.944769978523254 1984-01-01 0.957819998264313 1985-01-01 0.997810006141663 1986-01-01 1.014060020446780 1987-01-01 1.022920012474060 1988-01-01 1.018429994583130 1989-01-01 1.013139963150020 1990-01-01 1.032899975776670 1991-01-01 1.012680053710940 1992-01-01 1.012369990348820 1993-01-01 1.019860029220580 1994-01-01 1.021510004997250 1995-01-01 1.010499954223630 1996-01-01 0.995109975337982 1997-01-01 0.982689976692200 1998-01-01 0.988499999046326 1999-01-01 0.992299973964691 2000-01-01 1.015660047531130 2001-01-01 1.038529992103580 2002-01-01 1.024219989776610 2003-01-01 1.031389951705930 2004-01-01 1.036239981651310 2005-01-01 1.035889983177190 2006-01-01 1.051360011100770 2011-01-01 1.017789959907530 2012-01-01 1.009840011596680 2013-01-01 1.018890023231510 2014-01-01 1.015269994735720 2015-01-01 1.012300014495850 2016-01-01 1.020830035209660