In 1837, the first English tea garden was established at Chabua in Upper Assam; in 1840, the Assam Tea Company began the commercial production of tea in the region, run by indentured servitude of the local inhabitants. Beginning in the 1850s, the tea industry rapidly expanded, consuming vast tracts of land for tea plantations. By the start of the 20th century, Assam became the leading tea-producing region in the world. But despite the discovery of the indigenous "Camellia sinensis" plant, the tea industry in India began with 42,000 seedlings germinated from a consignment of 80,000 seeds procured from China—2000 were planted in the hill districts of South India, and 20,000 each in the hill districts in Kumaon in North India and Upper Assam on the Northeast frontier. It was only later that the indigenous plants were used. Today, the Chinese strain produces Darjeeling tea and the indigenous Assamese variety produces the remainder of the tea produced in India. Writing in "The Cambridge World History of Food" , Weisburger & Comer write: The tea cultivation begun there [India] in the nineteenth century by the British, however, has accelerated to the point that today India is listed as the world's leading producer, its 715, 000 tons well ahead of China's 540, 000 tons, and of course, the teas of Assam, Ceylon (from the island nation known as Sri Lanka), and Darjeeling are world famous. However, because Indians average half a cup daily on per capita basis, fully 70 percent of India's immense crop is consumed locally. India was the top producer of tea for nearly a century, but recently China has overtaken India as the top tea producer due to increased land availability. Indian tea companies have acquired a number of iconic foreign tea enterprises including British brands Tetley and Typhoo. India is also the world's largest tea-drinking nation. However, the per capita consumption of tea in India remains a modest 750 grams per person every year due to the large population base and high poverty levels. From Rs 19,500 crore in 2011 (), the total turnover of the Indian tea industry is expected to be Rs 33,000 crore by 2015 () according to the ASSOCHAM report of 2011. The same report pegs 90 per cent of all Indian households as regular tea drinkers. The reasons stated are "tea is cheap, affordable, and addictive." However, the annual per capita tea consumption in India was only 0.52 kg per person in 2009.