Year	% female
1971	18.19917
1972	20.42065
1973	23.74841
1974	27.56614
1975	30.55399
1976	33.54282
1977	36.03215
1978	38.45601
1979	39.93528
1980	40.71854
1981	40.1601
1983	41.40762
1986	45.404
2002	50.51447
2003	50.49123
2005	53.25685
2006	52.90003