Year	Ratio
1971-01-01	0.941950023174286
1972-01-01	0.831990003585815
1973-01-01	0.882070004940033
1974-01-01	0.849200010299683
1975-01-01	0.866819977760315
1976-01-01	0.888559997081757
1977-01-01	0.865360021591187
1978-01-01	0.862030029296875
1979-01-01	0.838760018348694
1980-01-01	0.875519990921021
1981-01-01	0.853789985179901
1982-01-01	0.859619975090027
1983-01-01	0.880299985408783
1984-01-01	0.878099977970123
1985-01-01	0.965969979763031
1986-01-01	0.974789977073669
1987-01-01	0.975319981575012
1988-01-01	0.970669984817505
1989-01-01	0.940209984779358
1990-01-01	0.933220028877258
1991-01-01	0.927670001983643
1992-01-01	0.916469991207123
1993-01-01	0.914860010147095
1994-01-01	0.893400013446808
1995-01-01	0.930790007114410
1996-01-01	1.009789943695070
1997-01-01	0.975279986858368
1998-01-01	0.977079987525940
1999-01-01	0.931309998035431
2000-01-01	0.977800011634827
2001-01-01	0.952390015125275
2002-01-01	0.983470022678375
2003-01-01	0.994910001754761
2004-01-01	0.942910015583038
2005-01-01	0.959649980068207
2006-01-01	0.978600025177002
2007-01-01	0.956449985504150
2008-01-01	0.967270016670227
2010-01-01	0.893140017986298
2011-01-01	1.002699971199040
2012-01-01	1.026540040969850
2013-01-01	1.036290049552920
2014-01-01	1.046640038490300
2015-01-01	1.069749951362610
2016-01-01	1.042340040206910