tons of orange; 90 thousand tons of soy; 80 thousand tons of sorghum; 60 thousand tons of potato; 55 thousand tons of barley; 42 thousand tons of peanut; 38 thousand tons of cotton; In addition to smaller productions of other agricultural products. Mining sector As other southern African countries, Zimbabwean soil is rich in raw materials, namely platinum, coal, iron ore, and gold. Recently, diamonds have also been found in considerable deposits. Copper, chromite and nickel deposits also exist, though in lesser amounts. The Marange diamond fields, discovered in 2006 are thought to be among the richest in the world. In March 2011, the government of Zimbabwe implemented laws which required local ownership of mining companies; following this news, there were falls in the share prices of companies with mines in Zimbabwe. Various NGOs reported that the diamond sector in Zimbabwe is rife with corruption; a November 2012 report by NGO Reap What You Sow revealed a huge lack of transparency of diamond revenues and asserted that Zimbabwe's elite are benefiting from the country's diamonds. This followed former South African President Thabo Mbeki’s warning days earlier that Zimbabwe needed to stop its "predatory elite" from colluding with mining companies for their own benefit. Also in that month, the Associated Press reported that at least $2 billion worth of diamonds had been stolen from Zimbabwe's eastern diamond fields and had enriched Mugabe's ruling circle and various connected gem dealers and criminals. In January 2013, Zimbabwe's mineral exports totalled $1.8 billion. As of October 2014, Metallon Corporation was Zimbabwe's largest gold miner. The group is controlled by its Chairman Mzi Khumalo. In 2019, the country was the world's 3rd largest producer of platinum and the 6th largest world producer of lithium. In the production of gold, in 2017 the country produced 23.9 tons. Education The state of education in Zimbabwe affects the development of the economy while the state of the economy can affect access and quality of teachers and education. Zimbabwe has one of Africa's highest literacy rates at over 90%. The crisis since 2000 has, however, diminished these achievements because of a lack of resources and the exodus of teachers and specialists (e.g. doctors, scientists, engineers) to other countries. Also, the start of the new curriculum in primary and secondary sections has affected the state of the once strong education sector. Science and technology in Zimbabwe Zimbabwe's Second Science and