Year	Ratio
1971-01-01	0.227009996771812
1972-01-01	0.239910006523132
1973-01-01	0.245790004730225
1974-01-01	0.248820006847382
1975-01-01	0.382109999656677
1980-01-01	0.352160006761551
1981-01-01	0.463829994201660
1982-01-01	0.477560013532639
1983-01-01	0.463669985532761
1985-01-01	0.535899996757507
1986-01-01	0.566470026969910
1988-01-01	0.594709992408752
1990-01-01	0.492009997367859
1993-01-01	0.427529990673065
1994-01-01	0.377550005912781
1995-01-01	0.405310004949570
1996-01-01	0.437139987945557
1997-01-01	0.441219985485077
1998-01-01	0.432209998369217
1999-01-01	0.483190000057220
2000-01-01	0.523790001869202
2001-01-01	0.587419986724854
2002-01-01	0.562139987945557
2003-01-01	0.562919974327087
2004-01-01	0.617219984531403
2005-01-01	0.705470025539398
2006-01-01	0.673749983310699
2007-01-01	0.719389975070953
2008-01-01	0.773129999637604
2009-01-01	0.794380009174347
2010-01-01	0.766600012779236
2011-01-01	0.732590019702911
2012-01-01	0.822719991207123
2013-01-01	0.878719985485077
2014-01-01	0.932500004768372
2015-01-01	0.955169975757599
2016-01-01	0.999769985675812