Remarkably, the survey found higher levels of alienation among young people who had attended Catholic schools. Among respondents who had attended a Church-related school, 65% said that Church teaching on sexuality is outdated and 61% said that Mass attendance could be a boring obligation. Both figures were higher than the results for the overall sample.
And I state again the inflexible O'Brien's Law of Apostasy
There is no better indication that an adult has fallen away from the Faith than his having had 12 years of Catholic Education as a child.
Another way of stating it is
The chance that a Catholic will apostasize varies in direct proportion to that person's years in a Catholic School, and approaches 100% as the time spent in Catholic Schools approaches 12 years.