Kigali young, with 73 percent of residents being less than 30 years old, and 94 percent under the age of 50. In 2014, the proportion of people classified as living in poverty within Kigali was 15 percent, compared with 37 percent for Rwanda as a whole. The 2012 census recorded a workforce of 487,000 in Kigali. The city's biggest employment sector is agriculture, fishing and forestry, covering 24 percent of the workforce; utilities and financial services with 21 percent; trade 20 percent and government 12 percent. Mines for tin ore (cassiterite) have operated nearby, and the city built a smelting plant
Kigali part of the upper headwaters of the Nile, forms the western and southern borders of the administrative city of Kigali, although this river lies somewhat outside the built-up urban area. The largest river running through the city is the Nyabugogo River, which flows south from Lake Muhazi before flowing west between Mount Kigali and Mount Jali, and draining into the Nyabarongo. The Nyabugogo is fed by various smaller streams throughout the city, and its drainage basin contains most of Kigali's territory, other than areas in the south which outflow directly to the Nyabarongo. The rivers are flanked by wetlands, which