As late as the 19 50s, almost the entire population was indigenous. With the increase in oil revenues and consequent increase in development projects, a large, skilled labor force was needed, and Kuwait turned to expatriate workers. Foreign workers include Arabs (especially Egyptians and Palestinians), Iranians, Indians, Pakistanis, and more recently, Koreans and Filipinos. The manpower shortage is most acutely felt in the area of middle-management positions, in which few Kuwaitis seem to be interested. Consequently, a large number of middlemanagement positions are occupied by Palestinians, many of whom hold Jordanian passports.