Mining generated about 33.9% of GDP in 2012 and employed 12% of the population in 2010. Togo has the fourth-largest phosphate deposits in the world. Their production is 2.1 million tons per year. Since the mid-90s, however, there has been a decline in the mining industry, and the government will need to invest heavily to sustain it. The mining industry is facing difficulties due to falling phosphate prices on world markets and increasing foreign competition. There are also reserves of limestone, marble and salt.