Do four chars in a party cut down RAF EXP?

[Eggroll]

Hmm, that sounds right. But when I've leveled with a friend (normal, not boosted with RAF), and we are two people in our party, we received substantially less exp per mob than someone solo, even with the grouping bonus. Would this trend continue with four people? Or does RAF act as if you're getting SoloXPx3 or GroupedXPx3?