Year	% female
1971	20.75863
1972	23.63895
1973	22.79661
1974	23.05348
1975	22.62673
1976	23.25817
1977	22.80902
1978	22.81216
1979	23.40078
1980	23.81867
1981	24.02935
1982	25.03884
1983	24.90497
1984	24.66516
1985	23.97458
1986	23.54572
1987	23.45567
1988	24.33192
1989	23.73092
1990	25.39893
1991	25.27037
1992	24.7612
1994	25.67222
1995	26.06216
1996	26.15604
1997	26.61694
1998	28.50598
1999	28.88989
2000	30.92574
2001	31.37603
2002	32.38206
2003	33.0797
2004	34.05148
2005	34.56421
2006	35.09885
2007	34.27256
2008	34.58285
2009	34.62992
2010	34.93822
2011	36.34871
2012	37.19771
2013	38.16753
2014	38.7328
2015	39.95447
2016	40.65823
2017	42.04819
2018	42.72158