I tend to think "zero," but you do you, I guess.
Anyway...
https://www.elephantinthevalley.com
http://www.kaporcenter.org/tech-leavers/
https://mobile.nytimes.com/2017/06/30/technology/women-entre...
Etc.
Harassment is bad, but I don't think "unwanted sexual advances" should categorically count as harassment. It all depends (of course some advances can be harassment, but just because some attraction is unrequited it is not harassment) - it is human to be attracted and fall in love.
There's a big difference between:
"Hey would you like to go grab lunch with me sometime?" (ok if not overly persistent)
vs
"You're hot, want to have sex with me sometime?" (never ok at work)
And I would suggest some introspection about why your bar to be convinced is so high. The persistent and sometimes aggressive disbelief that women face from male colleagues when they complain about harassment is a big part of the industry problem.
It is also a very one-sided narrative, omitting the advantages that being attractive also brings.