Chester Ltd purchased a new machine for £2,000 on 1 January 2019. At that time, the company believed that its useful economic life would be 10 years, with no residual value.

On 1 January 2021, Chester Ltd changes its estimations. The company now believes that the machine will be used for a further 10 years after which time it will have a second-hand value of £200.

What is the depreciation charge for the year ending 31 December 2021?