Guild: Xen of Onslaught [XoO] Xen Of Heroes Division
Sometimes I see only one, other times I'll see up to three. Most times it's only 2 though. This is with me not farming that place or chest running. So it's usually about odds. I don't believe the farming code affects how many chests there will be in an area, I may be wrong. I don't believe A-net has changed the amount of chests that spawn though.