Year	% female
1971	28.92933
1972	29.02573
1973	29.00988
1974	29.29808
1975	28.70334
1976	29.03104
1977	30.25451
1978	30.22563
1979	30.22948
1980	30.64804
1981	32.29777
1982	33.0306
1983	34.59658
1984	34.77005
1985	35.46792
1986	35.25767
1987	36.33866
1988	37.30431
1989	37.80868
1993	37.88738
1996	37.7133
1999	37.59036
2000	37.02111
2001	36.63955
2003	40.46227
2004	38.91248
2007	41.44639