Year	Ratio
1970-01-01	0.692640006542206
1971-01-01	0.682730019092560
1972-01-01	0.710099995136261
1974-01-01	0.781560003757477
1979-01-01	0.927450001239777
1980-01-01	0.953549981117249
1981-01-01	0.972259998321533
1982-01-01	0.989870011806488
1983-01-01	0.993749976158142
1984-01-01	1.007789969444270
1985-01-01	1.015730023384090
1986-01-01	1.003479957580570
1987-01-01	1.025089979171750
1988-01-01	1.036069989204410
1989-01-01	1.043140053749080
1990-01-01	1.071930050849910
1991-01-01	1.054159998893740
1992-01-01	1.066249966621400
1993-01-01	1.072510004043580
1994-01-01	1.083739995956420
1995-01-01	1.092229962348940
1997-01-01	1.072350025177000
2014-01-01	1.083520054817200
2015-01-01	1.086619973182680
2016-01-01	1.063650012016300