Quantifying the problem will not give an accurate result, I am sure. Abuse does not involve just the church of course. There have so many cases of teachers and outside groups, such as leisure activities, let alone family members or close friends.
History has shown us that as far as child abuse is concerned the victims might not come forward for many a year/decade if at all.
However, we should welcome all attempts to help the victims who are identified. We can but hope, TTT.