Year	% female
1970	30.84087
1971	30.8561
1972	31.80119
1973	32.53531
1974	33.26387
1975	33.53325
1976	34.32794
1977	35.03665
1978	35.62399
1979	36.18359
1980	36.54352
1981	37.29543
1982	37.89648
1983	38.51006
1984	38.96835
1985	39.41149
1986	39.74847
1987	40.05692
1988	40.44098
1989	40.8706
1990	41.5362
1991	42.26603
1992	42.93048
1993	43.4027
1994	43.62638
1995	44.514
1996	44.96065
1997	45.63836
1998	46.07667
1999	46.54375
2000	46.83047
2001	46.95979
2002	47.1926
2003	47.37464
2004	47.70993
2005	47.89251
2006	48.12902
2007	48.55775
2008	48.39359
2009	48.28597
2010	48.30435
2011	48.38635
2012	48.4499
2013	48.56438
2014	48.59951
2015	48.59967
2016	48.68572
2017	48.7772
2018	48.87337