Year	Ratio
1977-01-01	1.074149966239930
1978-01-01	1.031569957733150
1979-01-01	1.691830039024350
1980-01-01	2.080490112304690
1981-01-01	1.064389944076540
1982-01-01	1.482079982757570
1983-01-01	0.870899975299835
1984-01-01	0.961790025234222
1985-01-01	0.829689979553223
1987-01-01	1.208840012550350
1988-01-01	1.181959986686710
1993-01-01	1.489359974861150
1996-01-01	2.506789922714230
2004-01-01	3.381419897079470
2005-01-01	2.718539953231810
2006-01-01	5.309229850769040
2007-01-01	2.330840110778810
2008-01-01	2.239500045776370
2009-01-01	2.568360090255740
2010-01-01	2.580319881439210
2011-01-01	1.741629958152770
2012-01-01	2.180370092391970
2013-01-01	2.000659942626950
2014-01-01	2.088439941406250
2015-01-01	1.902150034904480
2016-01-01	1.953609943389890