In the tutorial system, do you have the same tutor for all three years?

I understand that at Oxbridge pedagogy is through the tutorial system, and that you have a tutor for a length of time with only a few other students with you. But is the tutor the same for all three years? For example, in law at Oxford the first phase is the Law Moderations and you pass an exam in that phase after the first two terms. Is each term with a different tutor, or do you have the same tutor up until the examination? And after that Law Mods examination do you get a new tutor?