Year	Ratio
1970-01-01	0.798990011215210
1971-01-01	0.824090003967285
1972-01-01	0.814469993114471
2004-01-01	1.232740044593810
2011-01-01	1.253430008888240
2012-01-01	1.248469948768620
2013-01-01	1.221490025520320
2014-01-01	1.236999988555910
2015-01-01	1.307279944419860
2016-01-01	1.235339999198910