Can someone help me with this Runescape Glitch?

Well i have been playing Runescape for a while now but I think i have discovered a glitch. I was wondering around Runescape and i desided to attack These Outlaws(level 32). I was attacking them for about 10 Minutes untill i finnaly noticed that i was getting barely any experiance Exp. I would get only two Exp per Outlaw. It was quite unusual but I didn't know if it was supposed to be like that or not. Can some please help me out?