Year	% female
1971	8.75296
1972	9.06224
1973	14.44778
1974	18.29043
1975	20.11561
1976	20.49
1977	22.71034
1978	23.21429
1979	25.08684
1980	27.48699
1981	28.83396
1982	25.17971
1983	24.12132
1984	22.56301
1985	24.41436
1986	25.26232
1987	25.81533
1988	29.06258
1989	30.5725
1990	37.27887
1991	39.54744
1992	38.23303
1993	42.23419
1994	43.93305
1995	45.31512
1996	50.70466
1997	51.52879
1998	48.51973
1999	52.41588
2000	50.69978
2001	48.11728
2002	45.98187
2003	44.53033
2004	44.23176
2005	42.75883
2006	41.57938
2007	40.45263
2008	39.68661
2009	40.06898
2010	39.95378
2011	40.32254
2012	39.7482
2013	39.25866