Year	Ratio
1971-01-01	0.680040001869202
1972-01-01	0.630970001220703
1973-01-01	0.611630022525787
1974-01-01	0.610289990901947
2000-01-01	1.842479944229130
2001-01-01	1.989660024642940
2002-01-01	2.184309959411620
2008-01-01	2.310650110244750
2009-01-01	2.332829952239990
2010-01-01	2.304970026016240
2011-01-01	2.331059932708740
2012-01-01	2.052459955215450
2013-01-01	2.281069993972780
2015-01-01	1.726519942283630