Note this Report covers cases going back to 1949, they uncovered 400. If J.W's in the U.K did a similar, thorough trawl of all Congregation Records going back that far, let's pretend they haven't destroyed most of them, we know they have, but just pretend they are all available, how many Cases of Abuse would they uncover ? in a much smaller Org ?
Maybe the File destruction that has gone on was to protect the org. and its £££ from a proper investigation such as this.
Note too the Apology, and the things put in place to mitigate the harm done, by the C of E. Another contrast in attitude.