Just for interest: Brophy HS in Phoenix, in 1990 was known to have one-third muslim students. They were not there for conversion.
Daily mass for students? That might be offensive for those muslims?
Most local diocesan high schools are leaps and bounds ahead of the public high schools, academically speaking, so they were probably there for that.
I found that to be the case with the diocesan schools I attended. Parents were sending their children there for academics and/or sports, not for religious formation.
The high school I went to is really an academic powerhouse. It was located in a bad area, tuition was about 5k a year. They moved to a "less bad" area, and tuition went to 7k a year. Now, since nobody cares about Catholic education, or can't afford it, they moved to the area with the highest concentration of wealth in the state.
Now, tuition is over 11k a year (tuition only), and the racial demographic has changed completely. A good number of the students are Asian and Indian (non-Catholic) and Muslim, because that's who are getting the high paying jobs.
When I was there, parents did sacrifice to send their children there. We had a variety of students coming from a variety of backgrounds. At 5k a year, it was possible to do that. At 11k a year, it is now only the wealthy that are able to send their children there, and it is not at all for Catholic education, it is only for academics.