Meteors are leftovers of the same primordial stuff that made up earth, so a cross sample of them would largely share the same ratios as earth, minus the volatiles.
Logic would dictate that that is likely, though that statement itself isn't scientific. Do you have any sources to back that up? I could see a possibility where, perhaps, certain elements are more likely to coalesce into planetary bodies, and others into meteoroids. It could also depend on the location in the solar system where the formation occurred — the primordial dust cloud that made up the infant solar system, I would wager, would be far from uniform.