@ItsAllGoingToBeFine, yes I saw that too. But the report includes statements like
Our findings in this report suggest that current statistics of the prevalence of violence against women have been underestimated for decades, and instead, it is likely that every woman and girl will be subjected to violence, abuse, rape or harassment.
It appears from this sample that violence and abuse against women and girls is a universal experience, with only 0.3% of the sample reporting that they had never been subjected to any violence, harassment, abuse or harm.
So they are clearly making generalisations.
I should emphasise that I think this work is really valuable and has some very important findings - but it just can't say anything reliable about the prevalence of VAWG in the general population. The really interesting findings, to my mind, are about the hugely diverse characteristics of the women reporting violence, and the persistence of these experiences.