Year	% female
1971	18.99858
1972	18.67584
1973	19.23312
1974	20.04717
1976	23.74988
1977	22.30204
1978	23.34292
1979	23.74566
1980	25.86929
1981	32.70868
1982	33.64119
1983	34.35794
1984	35.75884
1985	35.61814
1986	35.47942
2007	31.47281