sentences:  Population density is 779.36 hab/km2, much higher than the national average of 91.3 hab/km2.Population density varies with the community itself; the municipality of Madrid has a density of 5,160.57 hab/km2, whereas the Sierra Norte has a population density of less than 9.9 hab/km2.The vast majority of the population lives in the capital and its metropolitan area, which is the most populated in Spain.