You are correct in what you say about the small percentage of abusing priests & religious. To be factual the figure is 7-7.5%; which means the remaining  92.5-93% are/were not abusers. The figure is however, just over 2% more than society in general. A figure could not be established for how many of those stayed silent; looked the other way; or did nothing about it. As for the enabling bishops, who choose institutional loyalty as their first priority, rather than the protection of children; well the figure is probably around the 80% or more, because the Curia laid the ground rules; the various popes upheld them & the bishops obeyed them. There is no "oversampling there" as you put it; those are the facts established by Judicial Reviews. The Australian Royal Commission issued further facts that included 40% of St John of God  ; 23% of Christian Brothers and a continuing list of other abusing religious orders in Australia. In Ireland the Christian Brothers were top of the leader board.