Peanut production in China contributes to the national economy. China has been the world's largest producer of peanuts by a substantial margin since at least 2006. The peanut was introduced to China by Portuguese traders in the 17th century and another variety was provided by American missionaries in the 19th century. During the 1980s, peanut production began to increase, a major factor being the household-responsibility system, which moved financial control from the government to the farmers. By 2012 it was producing 16.7 million tonnes of peanuts annually. Peanuts are often used to make peanut oil, a popular ingredient in Chinese, South Asian and Southeast Asian cuisine. Although China is by far the world's largest producer, the per capita consumption of peanuts in China as of 2009 was s