There was a large segment of Wednesday's program The Fifth Estate (prob one of the most respected nightly news journal in Canada) and also a few months back a full Dateline episode dealing with the problem as it occurs in the Jehovah's Witness faith.
Don't worry, there will be other religions exposed now that victims everywhere are wisening up to the fact that, when abused, the first person you should turn to is not your priest/pastor/clergyperson/whatever, but THE POLICE.
Im not sure what your question 'how many under the age of 18' is saying. By far the vast majority of the cases are referring to minors, thats why its a CRIME, not simply a church matter to be dealt with quietly.