Year	% female
1970	29.21034
1971	29.23971
1972	29.90941
1973	30.33168
1974	30.58662
1975	31.63401
1976	32.91847
1977	35.0377
1978	35.46318
1979	36.45141
1980	37.34917
1981	36.68995
1982	37.00953
1983	37.38876
1984	37.58988
1985	38.12117
1986	38.00177
1987	38.08691
1988	37.94617
1989	38.05087
1990	39.49335
1991	39.82943
1992	40.3486
1993	41.44421
1994	42.62455
1995	42.55383
1996	42.60213
1997	42.13963
1998	42.87142
1999	43.26635
2000	43.37776
2001	43.5829
2002	43.21904
2003	43.42074
2004	42.61262
2005	42.67066
2006	42.43635
2007	41.76527
2008	40.4072
2009	39.7096
2010	39.49598
2011	39.74372
2012	38.69595
2013	38.50641
2014	38.53721
2015	38.35036
2016	37.91614
2017	37.78358
2018	37.89879