Here is some data: AEK Athens F.C., league, Superleague Greece; Superleague Greece, champions, Olympiacos F.C.; AEK Athens F.C., ground, Athens; AEK Athens F.C., numberOfMembers, 69618.

Write a sentence that describes this data
AEK Athens F.C.'s ground is in Athens and they have 69618 members . They play in the Superleague of Greece of which Olympiacos FC are previous champions.