In order to balance the risks for each realm, the notion of "underpopulated" realms appears. These realms benefit from a few advantages, principally a reduction of the purchase costs of the hookpoints and the maintenance of the keeps.
Every month the list of the underpopulated realms will be updated on each server. When the servers are balanced, no realm benefits from this advantage. For the opening of New Frontiers, these balanced servers are Logres, Carnac & Ys. As for the other servers, the underpopulated realms are :
Avalon : Hibernia
Lyonesse : Midgard-Hibernia
Dartmoor : Hibernia
Brocéliande : Midgard
Orcanie : Midgard
Excalibur : Midgard
Prydwen : Hibernia
Stonehenge : Hibernia
I thought hibs had the least amount of players on excalibur