https://www.newsweek.com/priests-commit-no-more-abuse-other-males-70625

But based on the surveys and studies conducted by different denominations over the past 30 years, experts who study child abuse say they see little reason to conclude that sexual abuse is mostly a Catholic issue. "We don't see the Catholic Church as a hotbed of this or a place that has a bigger problem than anyone else," said Ernie Allen, president of the National Center for Missing and Exploited Children. "I can tell you without hesitation that we have seen cases in many religious settings, from traveling evangelists to mainstream ministers to rabbis and others."

The graph might be from the Shakeshaft report from 2004.

https://www.edweek.org/leadership/sexual-abuse-by-educators-is-scrutinized/2004/03

A draft report commissioned by the U.S. Department of Education concludes that far too little is known about the prevalence of sexual misconduct by teachers or other school employees, but estimates that millions of children are being affected by it during their school-age years.

Yet despite the limitations of the existing research base, the scope of the problem appears to far exceed the priest abuse scandal in the Roman Catholic Church, said Charol Shakeshaft, the Hofstra University scholar who prepared the report.

To support her contention that many more youngsters have been sexually mistreated by school employees than by priests, Ms. Shakeshaft pointed to research conducted for the U.S. Conference of Catholic Bishops and released late last month. That study found that from 1950 to 2002, 10,667 people made allegations that priests or deacons had sexually abused them as minors. (“Report Tallies Alleged Sexual Abuse by Priests,” this issue.)

Extrapolating from data collected in a national survey for the American Association of University Women Educational Foundation in 2000, Ms. Shakeshaft estimated that roughly 290,000 students experienced some sort of physical sexual abuse by a public school employee from 1991 to 2000—a single decade, compared with the roughly five-decade period examined in the study of Catholic priests.

10,667 allegations / 53 years = 201 cases per year

290,000 allegations / 10 years = 29,000 cases per year

So that seems to be how they got the numbers for the graph. Depends on how accurate the "extrapolation" is. But in any case, public schools have a massive pedo/grooming problem while the Catholic Church is peanuts compared to them. They were just a scapegoat used by the elite.