It entirely depends on the well and the formation. I have some old wells that are on top of oil bearing formations that got tilted vertically, and they have been producing for years…since the 1950s…on the other hand I have a newer well that is on its last legs after a couple of years. So there are many variables. The big new horizontal wells decline very rapidly…big checks at first then a rapid decline to a low level that will sustain maybe 10 years depending on the well. The average monthly check depends on the number of acres you have, your royalty rate, and the well production.