a study which analysed cases of convicted child abusers

No study based on convictions can be accurate.

Rape conviction rates are tiny. It's a given child rape conviction rates are far tinier, because most cases don't get to trial. Of those that do, it's far easier to secure a conviction when there's independent corroboration - for example, in a family - than it is to convict those in a position of authority.

The latter get dual protection. Not only is the abuser able to use a position of power to silence victims, but if accusations are made, the abuser can rely on higher political or religious authority to cover up the abuse.

This is exactly what happened in the Catholic church, in many of the UK's music schools, in the BBC, which seems to have been very good at protecting some of its entertainers, and is currently happening in Westminster, where serious questions based on written evidence - or sometimes the mysterious disappearance of written evidence - are being asked about important political names.