Sugar was the main crop produced on plantations throughout the Caribbean through the 18th, 19th, and 20th centuries. Most islands were covered with sugar cane and mills for refining it. The main source of labor, until the abolition of the system, was enslaved Africans. After slavery indentured laborers from India, China, and Java migrated to the Caribbean to mostly work on the sugar plantations. These plantations produced 80 to 90 percent of the sugar consumed in Western Europe.