"Meditrina how many Pakistani Bangledeshi Somalian Bengali East European Muslim children are in your local Catholic schools?"
Don't know exactly. As quoted above, it's pretty much in line with the Census stats quoted above: lots of newish arrivals from Eastern Eurooe (they go to Church, they find out about schools fom that community, they use them), and South Americans. Not that familiar with the school, but think there are usually a few families from the Phillipines too.
If there is a demand for atheist education (not sure if that's what gardenfeature is after) there are more possibilities now under the free school policy (would need a waiver about "collective worship" in same way as Muslim and Jewish school have, and the RE it must offer would be handled in the same way too).
Faith schools exist because churches, synagogues, mosques and temples founded them - many welll before state education existed at all (CofE in particular to educate all children in their parish, not just religious families). Now, with free school funding, groups do not have to fundraise extensive for a generation or two to set up, nor do they/their church have to raise the 10% capital costs, nor deal with the extra bureaucracy if dealing with both Church owners/funders and govt funders over land/buildings/maintenance/alterations etc. It's a good time to make the point by doing it, and doing it well.
Though most CofE schools are VC (fully community criteria), and also with VA schools (which may allocate some or all places by application of churchgoing activity), are more community focussed and agnostic than outsiders realise. And the loose liturgical stance of CofE does mean that just about anything short of advocating crime or satanism counts as "broadly Christian".