InvokeRepeating is not stoping.

I am trying to make enemy spawn using InvokeRepeating but any how i am not able to stop it when i have enough number of enemy Here is the code can any one tell me what went wrong.

     public GameObject enemy;                // The enemy prefab to be spawned.
     public float spawnTime = 7.0f;            // How long between each spawn.
     public Transform[] spawnPoints;         // An array of the spawn points this enemy can spawn from.
     public int LevelMaxEnemy=10;
     public int numofEnemy=0;
     void Start ()
     {
         // Call the Spawn function after a delay of the spawnTime and then continue to call after the same amount of time.
         InvokeRepeating ("Spawn", spawnTime, spawnTime);
 
     }
     
 
     void Spawn ()
     { 
         // If the player has no health left...
         if(PlayerMovementScript.playerHealth <= 0f)
         {
             // ... exit the function.
 
             return;
         }
         if(numofEnemy > LevelMaxEnemy){
             // ... exit the function.
             
             return;
         }
 
         else{
             // Find a random index between zero and one less than the number of spawn points.
             int spawnPointIndex = Random.Range (0, spawnPoints.Length);
             
             // Create an instance of the enemy prefab at the randomly selected spawn point's position and rotation.
             Instantiate (enemy, spawnPoints[spawnPointIndex].position, spawnPoints[spawnPointIndex].rotation);
             numofEnemy = numofEnemy + 1;
             
         }
 
     }