Year	% female
1971	18.92012
1972	17.30687
1973	16.52291
1976	18.03485
1977	17.94397
1978	21.17562
1979	21.34773
1980	25.82857
1981	26.40065
1982	26.32353
1986	26.96843
1987	28.84198
1988	27.82221
1989	29.15527
1990	28.74031
1991	29.37561
1992	29.38043
2001	34.64839
2009	36.15132
2011	35.86738
2012	34.26894
2016	39.29494
2017	40.13015