Swazi nation land, which comprises over 60% of the total land area, is held in trust by the crown for the Swazi people and supports about 70% of the population. Nearly half of the remaining land, which is freehold title, is owned by Europeans; the rest is owned by government or parastatal bodies. Under the traditional land tenure system, farmers till small plots, averaging less than three ha (7.4 acres), but have no title or right to sell this land. The average freehold title farm, by contrast, is about 800 ha (2,000 acres), and over 60% of freehold title cropland is irrigated. In this modern sector, agriculture expanded considerably in the early 1970s, mainly because of improved irrigation, better strains, and widespread introduction and use of fertilizers. Sugar is the most important cash crop, and corn is the staple crop. Most of the sugar produced is exported to Western Europe and North America. Output in 1999 included sugarcane, 3.7 million tons, and corn, 113,000 tons. Much of the sugar is exported to the EU, in accordance with the Sugar Protocol of the Lomé Convention; increasing amounts, however, are sold and refined domestically. Production of grapefruit in 1999 was about 25,000 tons; oranges, 31,000 tons; and pineapple, 8,000 tons. Cotton fiber production in that year was 6,000 tons. Between 1970 and 1982, 17 Rural Development Areas were established to assist traditional farmers; the program was planned to extend eventually to all Swazi nation land. The 1991/92 drought caused corn and cotton production to seriously decline; as a result the government sought emergency food assistance. By 1999, crop production was 90% of what it had been during 1989–91.