Year	Percent
1971	92.8569
1972	92.327
1975	93.9272
1976	94.50414
1977	94.56911
1978	95.89336
1979	96.11534
1980	96.87409
1986	96.57399
1987	95.54329
1988	99.02423
1989	101.43351
1990	104.64536
1991	106.65993
1992	107.682
1999	97.11818
2000	97.52818