If a country has 1 billion population

If a country has 1 billion population but has only one car, even if this car kills 100 people/day, if calculate death/capita, it will be small.  But you cannot say car is safe in this country.  In other words, death/capita is meanless.  Death/car is more meaningful and that data is available in the link you provided. 

Ideally, death/car/hour is even more meaningful but such data would be hard to obtain.