Year	% female
1975	23.90332
1976	27.85587
1977	29.01997
1978	29.75449
1979	30.21698
1981	32.15085
1982	31.32404
1986	28.84149
1990	27.59833
1992	29.52719
1994	30.5022
1997	32.03758
1998	29.69066
1999	30.09295
2004	33.17274
2007	35.13166