I've spent the past hour reading these studies and you are correct to ask about the definition. The AAUW definition includes teachers telling inappropriate jokes to students. Other studies use more limiting definitions. Still, the estimates for students subject sexual misconduct from teachers (or school employees) range from 4 to 50 percent! I cannot figure out out to quote PDF charts, so I will provide a link
table 5 under chapter 3.2 compares these rates and from that report, I think the percentage of U.S. schoolchildren who experience physical sexual abuse is around 7 percent (for 2000 - the numbers are significantly higher for the 1970s and early 1980s). Unfortunately I cannot compare that the RCC's rate, because I cannot find a published rate for them.