Remember that it's a continuum. There are people who are at the early phase of radicalization, and that can grow all the way to very severe radicalization.
There aren't very good statistics in North America or elsewhere, but I think if you look at related conditions like the rise of pornography addiction and things like video game addiction, these are oftentimes comorbid. When you have someone who is addicted to pornography, the likelihood that they're engaged in anti-feminist ideology is high.
What we're basically seeing is probably somewhere between 6% and 15%. That would be my guess, depending on the study.