A district (sum; Mongolian: сум, arrow, sometimes spelled soum or—from the Russian form—as somon) is a second level administrative subdivision of Mongolia. The 21 Provinces of Mongolia are divided into 331 districts On average, each district administers a territory of 4,200 km2 (1,600 sq mi) with about 5,000 inhabitants, primarily nomadic herders. It has total revenues of 120 million Tögrög, 90% of which comes from national subsidies.