There are ex-cadets at Ryanair, Easyjet, Cityjet, Aer Arann, BA, Monarch, Flybe, Thomsonfly, GB, Baby, to name some off the top of my head. Obviously people will have their reasons for staying or returning, but it doesn't take a genius to work out which of these companies offer an inferior overall package to Lingus and thus, make a good guestimate as to who will or won't return. I'd say the previously mentioned figure of 30-35 would be about right. That said, if the package ain't good enough, that figure will reduce substantially. Bear in mind most of the cadets now have substantial jet time, and some have commands, so they have plenty of options and are far beyond being starry-eyed low-timers.