@ArabellaScott Did you have any sources for suggesting that transwomen are at risk when using men's single sex spaces, for example? From what I've read, they're the safest demographic in the UK.
I don't know any trans women who use men's spaces in the UK so I expect trying to find stats on that would be as difficult as trying to find stats on how many non trans women have been attacked in male spaces.
There is some evidence from the US which shows that trans students who were not allowed to use toilets inline with their gender identity were at higher risk of sexual assault. I haven't actually read the full study yet but there's a summary below (from here: edition.cnn.com/2019/05/06/health/trans-teens-bathroom-policies-sexual-assault-study/index.html)
Researchers analyzed data from 3,673 adolescents in the LGBTQ Teen Study, an anonymous web-based survey of US kids ages 13 to 17. Students who reported being told by teachers or staff that they could not use restrooms or locker rooms consistent with their sexual identity at school were classified as having "restrictive access."
Just over 1 out of every 4 students in the study, or 25.9%, reported being a victim of sexual assault in the past 12 months. Transgender and gender-nonbinary teens who were subject to restroom or locker room restrictions had an even higher prevalence of sexual assault, at 36%, according to the findings, published Monday in the journal Pediatrics.
The national transgender survey in the US, with a huge sample size, found that 37% of trans women had been sexually assaulted in their lifetime and 10% of trans people overall had been sexually assaulted in the last year. Shockingly it also found half of trans men had been sexually assaulted in their lifetime. Both these figures are higher than reported assaults on non trans men and women and I do suspect that gender ambiguity may actually attract predatory men, possibly because they think trans people won't be believed, or won't report it, or as I mentioned earlier see them as a sexualised subclass to whom the normal rules of behaviour don't apply.
The survey also found that 13% of trans people had been physically assaulted in the last year, and 5% of trans people reported being physically attacked in public by a stranger in the last year. Trans people of colour across all measures were even more likely to face both physical and sexual assaults. (www.transequality.org/sites/default/files/docs/USTS-Full-Report-FINAL.PDF)
I really don't think the claim of trans being the safest demographic stands up very well in the face of the evidence.