If you ask me (as someone did in the comments on yesterday's post) how many female grad students I am advising, I could tell you the exact number, although I won't. If, however, you ask me the number I have advised over my entire career, I could not have told you before looking up the data, as I just did.
This was interesting because, until I looked it up, I was very unsure about the specific ratio of female to male advisees. My uncertainty related in part to the fact that "advising" isn't always an exact thing. There are students with whom have I interacted quite a lot, but I was not their adviser. There have been students whom I advised for years, but then they dropped out for various reasons; they don't show up my official database of advisees, although some of them loom large in my advising memories. Also, I have been a professor at two universities, and I have been a real or honorary adviser of students at universities in other countries. Of all these advising experiences, I only counted those who graduated with me as the adviser or co-adviser of record.
According to that method of counting, the female : male ratio of my total advisees over my career to date is ~ 50 : 50.
I have absolutely no idea how this ratio relates to the number who have applied or otherwise expressed interest in working with me, but my general impression, which could well be unreliable, is that the actual ratio reflects the applicant ratio.
So, those are my data. There have been fluctuations in the ratio over the years -- including some times with no or very few women in my research group -- but overall I am quite happy with the numbers (and with the students themselves).