Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Another sign of a species' state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Answer: population density
A:
What is the term for the average number of individuals in a population for a given area?