Year	Percent
1980-01-01	4.7500000000000000
1981-01-01	4.1041700000000000
1982-01-01	4.0000000000000000
1983-01-01	4.0000000000000000
1984-01-01	4.0000000000000000
1985-01-01	4.2708300000000000
1986-01-01	2.4166700000000000
1987-01-01	3.8666699999999996
1988-01-01	2.5025000000000000