(a) You must pay an advanced royalty monthly equal to the average monthly royalty you paid under 30 CFR part 1206, subpart H (including the amount against which you applied the annual rental as a credit) for the last 3 years the lease was producing. If your lease has been producing for less than 3 years, then use the average monthly royalty payment for the entire period your lease has been producing continuously;

(b) The ONRR must receive your advanced royalty payment before the end of each full calendar month in which no production occurs;

(c) You may credit any advanced royalty you pay against production royalties you owe after your lease resumes production. You may not reduce the amount of any production royalty paid for any year below zero.