The motor vehicles at cost account had a balance of $90000 at the beginning of the year on 1 January. On 1 September in the same year, the following transactions took place. 1 A motor vehicle was disposed of. The vehicle had been purchased in the previous year for $21 000. 2 A new motor vehicle was purchased at a cost of $24000. Depreciation is calculated at 20% using the straight-line method. Depreciation is charged on a month-by-month basis for each month the motor vehicle is owned. What was the depreciation charge for the year ended 31 December?