Yunnan Province is a largely mountainous province bordering on Burma, Laos, and Vietnam. It is home to the richest variety of ethnic groups in China. Its 24 registered minorities account for 34% of the population. The largest groups are the Yi, Bai, Zhuang, and Dai. Yunnan is rich in flora and fauna, and is home to half of all of China's plant and animal species. It has the nation's richest deposits of non-ferrous metals such as lead, zinc, and germanium and also the largest phosphorous reserves. Agricultural products include sugarcane, rubber, and bananas. Yunnan is China's main source of tobacco and cigarettes. Tobacco accounts for 70% of the provincial government's revenue. China's annual consumption, estimated at 1,700,000,000,000 cigarettes is a staggering average for 1,400 for every man, woman and child.