Libya is a large country with a relatively small population, and the population is concentrated very narrowly along the coast. Population density is about  in the two northern regions of Tripolitania and Cyrenaica, but falls to less than  elsewhere. Ninety percent of the people live in less than 10% of the area, primarily along the coast. About 88% of the population is urban, mostly concentrated in the three largest cities, Tripoli, Benghazi and Misrata. Libya has a population of about  million, 27.7% of whom are under the age of 15. In 1984 the population was 3.6 million, an increase from the 1.54 million reported in 1964.