Answer: The figure "Net Migration Rate" is best understood within the "population" theme of geography.
Step-by-step explanation:
The figure "Net Migration Rate" is a demographic statistic that measures the difference between the number of people who migrate into a country and the number of people who migrate out of the country.
In geography, this type of demographic statistic is generally associated with the "population" theme, which focuses on the distribution, composition, and growth of human populations.