Sami has bought a truck for use in his business. The truck cost 9,000 and Sami hopes to sell it for 1,000 when he is finished using it in 4 years time. The truck will need maintenance every 2 years. If maintained well, trucks of this type last on average 10 years. Sami bought the truck from Ford Truck Services. Similar trucks cost between 7,000 and 10,000 but Sami particularly liked the features this truck has. 

What is the annual depreciation charge?