Tanks: Paladin, Warden, Barbarian, DK.
Healers: Priest, Druid, Shaman and Necro.
Casters: Mages and Warlocks
Ranged: Ranger and Hunter
Meelee: Seeker, BD and Rogue
Undefined: Charmer
Percentages:
25% Tanks
25% Healers
12.5% Casters
12.5% Ranged
18.75% Meelee
6.25% Undefined