It may seem to some that it is raining Canadians, (I hope that is a good thing), but stats from the Jamaica Tourist Board (as of 2012) indicate you are by far most likely to bump in to an American tourist on the beach, then a Canadian, then a Citizen of the UK, then a Deutschlander.
Lots of stats in the attached link, (if you like that sort of thing!).

http://www.jtbonline.org/statistics/...ics%202012.pdf