Year	Ratio
1970-01-01	0.788240015506744
1971-01-01	0.661539971828461
1973-01-01	0.633509993553162
1974-01-01	0.610400021076202
1975-01-01	0.567130029201508
1977-01-01	0.565970003604889
1978-01-01	0.550369977951050
1979-01-01	0.610700011253357
1981-01-01	0.760309994220734
1983-01-01	0.676429986953735
1984-01-01	0.666469991207123
1985-01-01	0.696219980716705
1986-01-01	0.706539988517761
1994-01-01	0.497860014438629
2010-01-01	1.785619974136350
2011-01-01	1.699259996414180
2012-01-01	1.598739981651310
2013-01-01	1.547039985656740
2014-01-01	1.289569973945620
2015-01-01	1.539420008659360
2016-01-01	1.552620053291320