My prefabs aren't keeping the float value for speed on the mover script,Im having a problem when a new prefab is spawned it doesn't keep the floated value for speed

The mover script

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class MeteorMover : MonoBehaviour { public float speed = -2f;

 Rigidbody2D rigidBody;

 // Start is called before the first frame update
 IEnumerator Start()
 {
     rigidBody = GetComponent<Rigidbody2D>();
     // Give meteor an initial downward velocity 
     rigidBody.velocity = new Vector2(0, speed);

     WaitForSeconds wait = new WaitForSeconds(1);
     int time = 1;
     w$$anonymous$$le (time > 0)
     {
         speed -= .1f;
         time++;
        //yield return speed;
         yield return wait;
     }
     //yield return speed;
     yield return wait;
 }

} The spawner script System.Collections; using System.Collections.Generic; using UnityEngine;

public class MeteorSpawn : MonoBehaviour { public GameObject meteorPrefab; public float minSpawnDelay = 1f; public float maxSpawnDelay = 3f; public float spawnXLimit = 6f;

 // Start is called before the first frame update
 void Start()
 {
     Spawn();
 }

 void Spawn()
 {
     // Create a meteor at a random x position
     float random = Random.Range(-spawnXLimit, spawnXLimit);
     Vector3 spawnPos = transform.position + new Vector3(random, 0f, 0f);
     Instantiate(meteorPrefab, spawnPos, Quaternion.identity);
     
     Invoke("Spawn", Random.Range(minSpawnDelay, maxSpawnDelay));
 }

}