Figure 4.

I see a green curve, seems like Koppelaar CO + NGL ,2006, going out of the graph, never coming back in. Is this correct? Stranger even more so that Koppelaars' ALL, 2005, is less then CO + NGL, 2006.

I also note similar declines on the backslope of the curve for all (except this strange green curve going out of the graph) scenarios; all curves show the same steepness. I didn't know there was such a consensus on decline rate.

My understanding is that the last Koppelaar's estimate is preliminary and not complete. He`s presently working on a new report.