On average, or by percentile? Because I think one is more likely to be revealing than the other. A 1Mt device might only have a 50% chance of killing 1+ people

On average, or by percentile? Because I think one is more likely to be revealing than the other. A 1Mt device might only have a 50% chance of killing 1+ people if detonated at the proper altitude at a random location within the US, (47% of the US is uninhabited) but average 1000 deaths (~6mi lethal radius, US overall population density of 90p/sqmi).