The Australian numbers are of all sexual abuse reported in the time frame. The numbers would be quite different if only abuse by an appointed man was reported.
Catholic numbers are abuse only by ordained clergy. They're not really comparable statistically. We would need a more refined data base.
However, any abuse is disgusting and should be reported. The issue with the Watchtower is that they do not have a fixed policy covering every entity (State, Province, county, etc.) Reluctance to report has caused their problems. For decades the Witness Governing Body lived in an idealized "spiritual paradise" and were reluctant to report any wrong doing, no matter how egregious, because doing so would destroy the spiritual paradise myth. They brought the negative reporting and court cases on themselves.
Another issue is press reporting. If a Baptist rapes his daughter, the press never says, "a Baptist man raped his daughter" unless he is clergy. The media identifies the perpetrator as a Witness regardless of official standing. This corrupts numbers too.