Year	% female
1970	57.77333
1971	53.39048
1972	53.0373
1973	52.56788
1974	53.36061
1975	54.78188
1976	56.15808
1977	57.44278
1978	57.39341
1979	59.50668
1980	59.61036
1981	60.0377
1982	59.84748
1983	60.76952
1984	60.01073
1985	59.42749
1986	59.95501
1987	60.52069
1988	60.35931
1989	59.53533
1990	59.76503
1991	59.21369
1992	59.32942
1993	59.20415
1994	59.393
1995	59.40801
1996	58.87271
1997	58.53935
1998	59.90851
1999	57.43474
2000	56.7939
2001	56.0749
2002	56.28513
2003	55.93353
2004	55.84965
2005	55.86706
2006	55.96065
2007	56.75033
2008	57.25582
2009	57.94761
2010	57.70881
2011	57.55781
2012	57.17236
2013	57.0134
2014	57.28207
2015	57.19147
2016	57.26666
2017	57.18016