bengal coal limited leased a colliery on 1st January 2004 at a minimum rent of Rs. 15,000 merging into a royalty of Re.1 per ton with a stipulation to recoup shortworkings over the first three years of the lease. The output for the first four years of the lease was 8000, 13000, 21000 and 18000 tons respectively. Draft the necessary journal entries of the books of the company giving effect to the above​