Year	% female
1970	24.31233
1971	30.30501
1972	35.35282
1973	35.43866
1974	36.94559
1975	38.86376
1976	43.09214
1977	40.93919
1978	46.53925
1979	47.99501
1980	45.78358
1981	44.88292
1982	44.77417
1983	44.45724
1984	41.70027
1985	42.80655
1986	44.13026
1987	42.32639
1988	39.31953
1989	35.4511
1990	33.99689
1991	31.19783
1992	28.59951
1993	28.82648
1994	29.23396
1995	29.62883
1996	30.11998
1997	29.2417
1998	29.84349
1999	32.62612
2000	38.60482
2001	35.39799
2002	32.45319
2003	30.2392
2004	28.92703
2005	30.24621
2006	31.55812
2007	32.90273
2008	31.9763
2009	32.49637
2010	31.32566
2011	30.47163
2012	29.91973
2013	28.0439