Year	Percent
1972	62.82074
1973	61.38044
1975	84.54133
1976	88.4225
1977	80.96873
1978	81.13906
1979	82.33409
1980	81.16285
1981	84.93515
1982	86.75219
1983	86.54248
1984	75.4321
1985	92.56023
1987	68.74302
1988	67.78181
1989	66.27483
1992	59.70086
1995	66.05642
1996	66.81676
1997	69.11031
2002	73.87439
2003	71.91822