China is Angola's biggest trade partner and export destination as well as the fourth-largest source of imports. Bilateral trade reached $27.67 billion in 2011, up 11.5% year-on-year. China's imports, mainly crude oil and diamonds, increased 9.1% to $24.89 billion while China's exports to Angola, including mechanical and electrical products, machinery parts and construction materials, surged 38.8%. The oil glut led to a local price for unleaded gasoline of £0.37 a gallon.