construction contracts-revenue

On 1 October 2008 Pricewell entered into a contract to construct a bridge over a river. The agreed price of the bridge is £50 million and construction was expected to be completed on 30 September 2010. The £14·3 million in the trial balance is: materials, labour and overheads 12,000 specialist plant (acquired 1 October 2008) 8,000 payment from customer (5,700) The sales value of the work done at 31 March 2009 has been agreed at £22 million and the estimated cost to complete (excluding plant depreciation) is £10 million. The specialist plant will have no residual value at the end of the contract and should be depreciated on a monthly basis. Pricewell recognises profits on uncompleted contracts on the percentage of completion basis as determined by the agreed work to date compared to the total contract price. MY solution: Estimated Profit: Rev: 50000- total costs (12000+8000+10000+2000dep) est profit = 18000 %completed =44% statement of P/L: Revenue=22000 COS=14080 and thus profit=7920 statement of financial position costs to date= 22000(12+8+2dep)+7920-5700=24220 (contract asset) this answer is different from that in the solution. They have no taken the depreciation in costs to date. could you please explain a bit on this? thanks :)