that depends on where your from. I used to travel a lot, and there are areas, EVERYONE hits or gets hit by deer. every few years pretty much. Some areas, with the traffic flows considered, odds are miniscule. Theres no real rule for rural, or city, terrain (flat or mountain) or population. It just seems like its a fact in some places, and a freak happenstance in others.
Related tip: Never report "I just hit a deer". Always report "a deer just hit me" No matter what side of the vehicle the collision happened