Year Ratio 1981-01-01 0.306349992752075 1984-01-01 6.420169830322270 1985-01-01 2.037420034408570 1989-01-01 3.777699947357180 1991-01-01 0.806649982929230 1992-01-01 1.436619997024540 1993-01-01 1.004140019416810