The majority of the Arabian population is sedentary, concentrated around oases, notably in the Nejd (central Arabia) and the Hejaz (along the northeast coast of the Red Sea). Agriculture is the main occupation, with dates, grains, and fruits the chief crops; pastoral nomads raise goats, cattle, sheep, and poultry. Until the mid-20th cent., when oil was discovered in E Arabia, the peninsula's main exports were hides, wool, coffee, spices, camels, and the famed, highly bred Arabian horses; in W Arabia pearls were exported. With the exception of Aden, Arabia did not have a good port until after World War II, when modern port facilities were constructed, especially along the Persian Gulf. Arabia has the largest oil reserves in the world, in addition to great amounts of natural gas. Saudi Arabia is the world's leading exporter of oil. Until the early 1970s, oil firms from the United States, Britain, and to a lesser extent Japan, had a monopoly on drilling concessions. However, the Arabian nations acquired much greater control over oil exploration, production, and price controls after 1970. Modern technology and the huge wealth generated by oil resources have profoundly altered traditional life in Arabia. Flourishing private enterprise, new transportation links, rapidly growing cities, a large foreign labor presence, and rising education and living standards characterize much of the peninsula.