To get an idea of what this actually means you need to compare different universities with the same or similar programmes. And ideally have some idea why the remaining 37% are not in employment after a year:
are they going on to study or internships?
having families?
taking a gap year?
reluctant to move away from home in search of employment?
in an area of high unemployment (in which case only the ones who choose to stay there will be affected)?
in a field where it is very difficult to get work if you do not have further training?