At a quick glance they look fine if that was done at operating temp. Cylinder 5 is either low compression, (but not horrible, just lower than the rest) or it's slightly clogged. Nothing to worry about though. Try do the DIY GM injector cleaner to see if that clears the clog some. If not then you may have a bad valve seal or something minor lowering compression a tad. Of course all that is based on fuel rate as mentioned... but it's the basic diagnosis from the info given.