Well, I don't see how else it could work. Certainly all 50 will be selected because they have the potential to pass the course, but it must be accepted that not all will. What the target figure is, I have no idea, but don't worry about it. If you all make the grade, you will all pass. The standards are set by the CAA, they are not adjusted by NATS to give them the correct number of passes (despite the fevered rumours about the 'numbers game' in the student common room when I was going through the sausage machine).