Considering that non government schooled kids have taken first several times or placed in the last 10 years far, far out of proportion to their numbers is quite extraordinary. Don't expect _too_ much press on that little factoid.
The fact is, they don't want any competition. The standard, dumbed down feeble response many parents have is "They don't get socialized."; which I presume to mean the kids are not exposed to mind numbing racism, drugs, homosexuality, etc. (by the faculty) and various leftist pet causes ad nauseum.