Year	Ratio
1971-01-01	0.987559974193573
1972-01-01	0.997200012207031
1973-01-01	0.996460020542145
1974-01-01	0.987779974937439
1975-01-01	0.945649981498718
1976-01-01	0.925429999828339
1977-01-01	0.930630028247833
1978-01-01	0.929859995841980
1979-01-01	0.931259989738464
1980-01-01	0.927869975566864
1981-01-01	0.946529984474182
1982-01-01	0.941810011863709
1983-01-01	0.950559973716736
1984-01-01	0.951279997825623
1985-01-01	0.943750023841858
1986-01-01	0.822549998760223
1988-01-01	0.912370026111603
1993-01-01	0.988990008831024
1994-01-01	0.941640019416809
1995-01-01	0.931460022926331
1996-01-01	0.983420014381409
1997-01-01	0.993849992752075
1998-01-01	0.932630002498627
1999-01-01	0.971740007400513
2000-01-01	0.965409994125366
2001-01-01	0.947319984436035
2002-01-01	0.945569992065430
2003-01-01	0.995980024337769
2004-01-01	0.961290001869202
2005-01-01	0.970889985561371
2007-01-01	0.983929991722107
2008-01-01	0.948819994926453
2009-01-01	0.943300008773804
2010-01-01	0.965910017490387
2013-01-01	0.961120009422302
2014-01-01	0.983600020408630
2015-01-01	0.963729977607727
2016-01-01	0.965640008449554