Relier Pairs Measuring populationsVersion en ligne Now you have to relate the terms with its definition. par Laura Jiménez Ruiz 1 Natural increase 2 Immigrant 3 Absolute population 4 Actual increase 5 Population density 6 Emigrant The average number of people who live in each square kilometre of land. A person who moves into an area. Includes the natural increase, the immigrants arriving and emigrants leaving. The difference between the number of births and the number of deaths. The total number of people living in an area. A person who moves away from an area.