I’m surprised that the rates are as high as they are. TOS had only 1 female character in the main cast. TNG (after Tasha left), DS9 and ENT only had two. So disregarding any guest characters the female main characters don’t have a lot of choice of whom to talk to, if they want to pass the test.
Well as the article points out, guest or secondary (like Guinan) characters helped out in TNG’s case (which, from memory, makes sense … one thing I remember noticing about TNG was how often a guest character in a position of power would be a woman, and sometimes a non-anglo one).