Coal mining produced almost 4 million tonnes of coal in 2014, of which 44% was exported. In 2016 it was down to 2,834,956 tonnes. New Zealand coal reserves are in excess of 15 billion tonnes, mainly in Waikato, Taranaki, West Coast, Otago and Southland. Over 80% of the reserves are in Southland lignite deposits worth $100 billion. Coal is produced from four underground and 21 opencast mines.