Year	Ratio
1971-01-01	0.129539996385574
1972-01-01	0.140630006790161
1973-01-01	0.161129996180534
1974-01-01	0.175459995865822
1975-01-01	0.195600003004074
1976-01-01	0.222420006990433
1977-01-01	0.254280000925064
1978-01-01	0.246920004487038
1979-01-01	0.275680005550385
1980-01-01	0.347699999809265
1981-01-01	0.361930012702942
1982-01-01	0.376190006732941
1983-01-01	0.379640012979507
1992-01-01	0.871869981288910
1999-01-01	0.991159975528717
2000-01-01	0.992070019245148
2001-01-01	1.054460048675540
2002-01-01	1.107959985733030
2003-01-01	1.106780052185060