Year	Ratio
1971-01-01	0.555959999561310
1972-01-01	0.480040013790131
1976-01-01	0.434529989957809
1977-01-01	0.301939994096756
1978-01-01	0.222680002450943
1979-01-01	0.192239999771118
1980-01-01	0.199709996581078
1981-01-01	0.242550000548363
1982-01-01	0.210899993777275
1983-01-01	0.246360003948212
1984-01-01	0.231610000133514
1985-01-01	0.271739989519119
1987-01-01	0.336250007152557
1988-01-01	0.346850007772446
1989-01-01	0.466010004281998
2000-01-01	0.541869997978210