rice (1.31 million tonnes), and millet (1.04 million tonnes). Sugar was the largest cash crop on the mainland in 2013 (296,679 tonnes), followed by cotton (241,198 tonnes), cashew nuts (126,000 tonnes), tobacco (86,877 tonnes), coffee (48,000 tonnes), sisal (37,368 tonnes), and tea (32,422 tonnes). Beef was the largest meat product on the mainland in 2013 (299,581 tonnes), followed by lamb/mutton (115,652 tonnes), chicken (87,408 tonnes), and pork (50,814 tonnes). According to the 2002 National Irrigation Master Plan, 29.4 million hectares in Tanzania are suitable for irrigation farming; however, only 310,745 hectares were actually being irrigated in June 2011. Industry, energy and construction Industry and construction is a major and growing component of the Tanzanian economy, contributing 22.2 per cent of GDP in 2013. This component includes mining and quarrying, manufacturing, electricity and natural gas, water supply, and construction. Mining contributed 3.3 per cent of GDP in 2013. The vast majority of the country's mineral export revenue comes from gold, accounting for 89 per cent of the value of those exports in 2013. It also exports sizeable quantities of gemstones, including diamonds and tanzanite. All of Tanzania's coal production, which totalled 106,000 short tons in 2012, is used domestically. Only 15 per cent of Tanzanians had access to electric power in 2011, rising to 35.2 per cent in 2018. The government-owned Tanzania Electric Supply Company Limited (TANESCO) dominates the electric supply industry in Tanzania. The country generated 6.013 billion kilowatt hours (kWh) of electricity in 2013, a 4.2 per cent increase over the 5.771 billion kWh generated in 2012. Generation increased by 63 per cent between 2005 and 2012; Almost 18 per cent of the electricity generated in 2012 was lost because of theft and transmission and distribution problems. The electrical supply varies, particularly when droughts disrupt hydropower electric generation; rolling blackouts are implemented as necessary. The unreliability of the electrical supply has hindered the development of Tanzanian industry. In 2013, 49.7 per cent of Tanzania's electricity generation came from natural gas, 28.9 per cent from hydroelectric sources, 20.4 per cent from thermal sources, and 1.0 per cent from outside the country. The government has built a gas pipeline from Mnazi Bay to Dar es Salaam. This pipeline was expected to allow the country to double its electricity generation capacity to 3,000 megawatts by 2016. The government's goal is to increase capacity to at least 10,000 megawatts by 2025. According to