A machinery was purchased for Rs. 4,00,000 on April 1, 2008 and it was depreciated @ 10% p.a. on straight line basis. The method was changed w.e.f year 2011-12 and depreciation chargeable on March 31, 2011 was calculated on written down value basis. It was decided to implement it with retrospective effect. Calculate the amount to be debited or credited to profit and loss account for difference in depreciation amount.