Year	Ratio
1971-01-01	0.589179992675781
1972-01-01	0.602310001850128
1973-01-01	0.606320023536682
1974-01-01	0.611069977283478
1975-01-01	0.615360021591187
1976-01-01	0.605319976806641
1977-01-01	0.599619984626770
1978-01-01	0.598649978637695
1979-01-01	0.600629985332489
1980-01-01	0.605480015277863
1981-01-01	0.601409971714020
1982-01-01	0.599720001220703
1983-01-01	0.600069999694824
1984-01-01	0.597930014133453
1985-01-01	0.598699986934662
1986-01-01	0.602219998836517
1987-01-01	0.603380024433136
1988-01-01	0.609839975833893
1989-01-01	0.620959997177124
1990-01-01	0.631089985370636
1991-01-01	0.642620027065277
1992-01-01	0.651849985122681
1993-01-01	0.654190003871918
1994-01-01	0.658529996871948
1995-01-01	0.662710011005402
1996-01-01	0.665489971637726
1998-01-01	0.685199975967407
1999-01-01	0.699639976024628
2000-01-01	0.710929989814758
2001-01-01	0.724650025367737
2002-01-01	0.739920020103455
2003-01-01	0.750859975814819
2004-01-01	0.784850001335144
2005-01-01	0.801310002803802
2006-01-01	0.818229973316193
2007-01-01	0.838989973068237
2008-01-01	0.866330027580261
2009-01-01	0.886500000953674
2010-01-01	0.910120010375977
2011-01-01	0.927619993686676
2012-01-01	0.947329998016357
2013-01-01	0.967260003089905
2014-01-01	0.974290013313293
2015-01-01	0.974439978599548
2016-01-01	0.978280007839203