And of the 116, let's not forget that four of them were killed by an American pilot.

 Casualty rates could be due to a lot of factors.  Training, equipment, competence of officers-- the list could go on,  I'm sure.  I think frequency of troop rotation has an effect, also. It seems to me the deaths spike when a fresh and inexperienced regiment is rotated in.  Could be due to inexperience, and/or the enemy testing the new troops. 

In this case,  I'd guess it has a lot to do with deployment.  Canada's contingency is in one of the toughest, if not the toughest area to be in.  And much of that is due to the fact some of our allies have restrictions concerning where thier troops can be deployed, and what they can do.

Leaving us with a disproportionate burden.