Year	% female
1970	25.19174
1971	25.39728
1972	26.06786
1973	28.30623
1974	30.31054
1975	30.52229
1976	31.25957
1977	31.39507
1978	32.03161
1979	31.92068
1980	33.00026
1981	33.34999
1982	33.61446
1983	33.2419
1984	33.27477
1985	33.84405
1986	33.60237
1987	34.33604
1988	34.97948
1989	35.38686
1990	35.77985
1991	35.89421
1992	35.82055
1993	36.09496
1994	35.0788
1995	35.03976
1996	35.50791
1997	34.66415
1998	35.66257
1999	36.06265
2000	36.58135
2001	36.91428
2002	37.24825
2003	37.62896
2004	37.63413
2005	37.02702
2006	37.28889
2007	37.24101
2008	36.64375
2009	37.12806
2010	36.37496
2011	36.39369
2012	36.34511
2013	36.53124
2014	36.40632
2015	37.30792
2016	37.06732
2017	37.31399
2018	37.38778