Too much variance
This question is too broad. Different models, engine types, fuel systems, exhaust systems and engine configurations make this impossible to answer.
If you want to know about your car
You can get one of these and check various temperature ranges under various circumstances like pulling a load up a hill, driving in city traffic, cruising down the freeway and idling by putting your car under the load, driving for a bit and then stopping and checking yourself using the thermometer.
if your programming a solution for general use
If you are looking for a template solution and numbers for a particular app you are writing then I think you need to have a different way of looking at it that's threshold driven for alerting or some such solution. I think a MaxTemp view is more tenable than seeking averages across all of the various platforms.