Approximately 42.5 percent of the population is younger than 15 years of age, while 54.5 percent are between the ages of 15 and 64. Those aged 65 and older form 3 percent of the total population. Only two general censuses, in 1975 and 1993, have been carried out after independence. The most densely populated regions of the island are the eastern highlands and the eastern coast, contrasting most dramatically with the sparsely populated western plains.