Year	% female
1972	27.95529
1973	29.43233
1974	30.92217
1975	32.12327
1976	34.45087
1977	35.54665
1978	36.32532
1979	37.08143
1980	37.00055
1981	38.89188
1982	39.26199
1983	39.09757
1984	39.51067
1985	40.3402
1986	40.82481
1987	41.52869
1988	42.06494
1989	42.66306
1990	42.95258
1991	43.47139
1992	44.36545
1993	45.08852
1994	45.90543
1995	46.5262
1996	47.23349
1997	47.88075
1998	48.9095
2000	49.77594
2001	50.25373
2002	50.5373
2003	51.03977
2004	51.79591
2005	52.10939
2006	52.2116
2007	52.18562
2008	52.25904
2009	52.57817
2010	52.6612
2011	52.65426
2012	52.49984
2013	52.71127
2014	52.62335
2015	52.62277
2016	52.83114
2017	52.78669
2018	53.07614