15. Network Rail shall, on receipt of a request from the Agency, from time to time provide the Agency free of charge with written estimates of the costs, charges, expenses and other liabilities for which the Agency is or will become liable under this Schedule (including the amount of the relevant costs mentioned in paragraph 14) and with such information as may reasonably enable the Agency to assess the reasonableness of any such estimate or claim made or to he made pursuant to this Schedule (including any claim relating to those relevant costs).