How do I add a limit zombies spawning in?

How do I add a limit zombies spawning in? Please help

Fine, Even though you didn't attempt. Here you go.

1. Add a Zombie to "ServerStorage"

2. Change the Zombies name to "Zombie"

Add this script into "ServerScriptService"

local zombie = game.ServerStorage.Zombie
local maxZombies = 250 -- Set this number to the max amount of zombies you want.
local currentZombies = Instance.new("IntValue")
currentZombies.Value = 0

while true do
	wait(0.1)
	if currentZombies.Value < maxZombies then
		repeat
			currentZombies.Value = currentZombies.Value + 1
			wait(5) -- This is the cool down time, set it to whatever you would like.
		until currentZombies.Value  == maxZombies
	end
end

while true do
	wait(0.1)
	if currentZombies.Value < maxZombies then
		repeat
			local z = zombie:Clone()
			z.Parent = game.Workspace
			local human = Instance.new("Humanoid")
			human.Parent = z
			if z.Humanoid.Health == 0 then
				currentZombies.Value = currentZombies.Value - 1
			end
			wait(5)
		until currentZombies.Value == maxZombies
	end
end

Your welcome..