How to change the lowest element in a list?

I wrote a script that would Instantiate gameobjects at a random spawnposition with lists. But now I want to get the element number, that contains the lowest number. I know that I can get the lowest value of multiple ones, but how to get the number of the element that contains the smallest amount?

 private void Start()
 {
     WaveStart();
     InvokeRepeating("Spawn", 10f, Random.Range(TimeSpan1, TimeSpan2));
 }

 private void Update()
 {
     if(Wave % 3 == 0)
     {

         TimeSpan1 = 0f;
         TimeSpan2 = 0.5f;
     }
 }

 void Spawn()
 {
     if (WaveStarted)
     {
         if (WavePoints == 0)
         {
             WaveStarted = false;
             Invoke("WaveStart", 5);
         }
         

         if (Wave % 3 == 0)
         {
             int lowest = Mathf.Min(ZombsPerSpawn[1], ZombsPerSpawn[2], ZombsPerSpawn[3], ZombsPerSpawn[4], ZombsPerSpawn[5]);
             
         }
         else if (Wave % 3 != 0)
         {
             chosenSpawn = Random.Range(0, Spawns.Count);
         }

         ZombsPerSpawn[chosenSpawn] += 1;

         if (WavePoints == 1)
         {
             GameObject cur1 = Instantiate(Zombies[0]);
             WavePoints = 0;
             cur1.transform.position = new Vector3(Spawns[chosenSpawn].position.x - 0f, Spawns[chosenSpawn].position.y + 0.6f, Spawns[chosenSpawn].position.z + 0.4f);
             
         }
         else if (WavePoints != 0)
         {
                 chosenzombie = Random.Range(0, Zombies.Count);
             if (WavePoints - Zombies[chosenzombie].GetComponent<PointsWorth>().Points >= 0)
             {
                 GameObject Zomb = Instantiate(Zombies[chosenzombie]);
                 Zomb.transform.position = new Vector3(Spawns[chosenSpawn].position.x - 0f, Spawns[chosenSpawn].position.y + 0.6f, Spawns[chosenSpawn].position.z + 0.4f);

                 WavePoints -= Zomb.GetComponent<PointsWorth>().Points;
             }
             else
             {
                  Spawn();
             }
         }
     }
 }

 void WaveStart()
 {
     WaveStarted = true;
     Wave += 1;
     WavePoints = (int)Mathf.Pow(Wave, 2) + 10;
 }