Percy,
In 2011 57% of school children in NI were catholic and 43% Protestant. Within a decade or so Catholics should be in the voting majority, which could make Northern Irish politics even more interesting if there is a move towards unification.
Obviously constituency boundaries may not mean that a catholic majority would translate to a political majority in the short term, but there would probably be a move towards this. Keep an eye out for constituency boundary reform in the next few years.....