Given the limited endurance of the fighters, in order to keep a reasonable force in the air, as many as ten times that number of aircraft would be needed, on the ground being repaired and refuelled after their patrols.
Given the limited endurance of the fighters, about an hour, in order to keep a reasonable force in the air as many as ten times that number of aircraft would be needed. At any given time only a few would be in the air, the rest would be on the ground being repaired and refueled after their patrols.