The oil-rich Nigerian economy, long caught in political instability, corruption, and poor macroeconomic management, is undergoing substantial reform under the new civilian administration. Petroleum is the leading mineral produced in Nigeria and provides about 95% of foreign exchange earnings and the majority of government revenues. Other minerals extracted include tin, iron ore, coal, limestone, columbite, lead, zinc, and gold. Industry in Nigeria includes the processing of agricultural products and minerals, and the manufacture of textiles, construction materials, footware, chemicals, fertilizer, and steel. Fishing and forestry are also important to the economy, and there is small commercial shipbuilding and repair sector. The largely subsistence agricultural sector has failed to keep up with rapid population growth, and Nigeria, once a large net exporter of food, now must import food.