Arch Coal will account for all Premiums, the Initial License Fee, the Development Costs and the *% return referred to in Section 4.1 and provide such accounting to ADA for each month by the tenth (10th) calendar day of the second month following the end of such month commencing in the month when Arch Coal first makes any sale of Enhanced Coal. (By way of illustration, the accounting for the month of June will be due by August 10th.) Ongoing Royalties shall be paid on a quarterly basis, no later than thirty-four (34) calendar days following the end of a calendar quarter, and shall be accompanied by a royalty report, which shall describe quantity and gross sales price of Enhanced Coal, evidence of (i) the then-current Index Price for non-Enhanced Coal, (ii) any deduction from and/or adjustments to the gross sales price as provided in the definition of Net Sales Price, and (iii) the calculation of Ongoing Royalties remitted. If Arch Coal fails to make any payment pursuant to this Agreement within the time specified herein, Arch Coal shall pay interest at a rate of one and one half percent (1.5%) per month on the unpaid balance finally determined to be due, payable from the due date until fully paid, and shall pay all costs of collection, including reasonable attorneys’ fees. The foregoing payment of interest shall not affect ADA’s right to terminate this Agreement in accordance with Section 10.