Year	Percent
1972-01-01	117.858
1973-01-01	112.191
1974-01-01	110.739
1975-01-01	114.973
1976-01-01	121.604
1977-01-01	105.427
1980-01-01	107.480
1981-01-01	96.081
1999-01-01	92.219