Spawn gameobject within a time window

In my project i am trying to get a gameObject to spawn randomly within a window of time. Every second, the gameObject should be spawned randomly between 0 and 1 seconds. A new game object cannot spawn until the entire second is up.

Here is my demo: http://soylentworks.com/codesucks/Builds/TouchnDrag.html You can see why i want to offset the time at which things spawn, since all 3 game objects come out at the same time.

In my code i created spawnWindow, and spawnWindowOpen to help with this, but i keep getting the wrong results. Read code comments for more detail.

Here is my current code for the Spawner object:

 using UnityEngine;
 using System.Collections;
 
 public class piSpawner : MonoBehaviour {
     
     public GameObject follower; // A single follower defined in prefab editor.
     public GameObject[] followers; // A group of followers defined in the prefab editor
     public float spawnRate = 1.0f; //The frequency at which followers spawn.
     private float nextSpawn = 0.0f; //used to trigger the next spawn
     private float nextSpawnWindow = 0.0f; // used to trigger SpawnWindow
     int followerIndex; // defines which follower to spawn
     float spawnRange; // defines the area in which the follower can spawn relative to th Spawner Object
     Vector3 spawnFromPoint; // tells the Spawner where to spawn something
     float spawnWindow; // The time interval in which a follower can spawn
     bool spawnWindowOpen = false; //a follower can only spawn if true
     
     void Start () {
         
         //this.gameObject.GetComponent<MeshRenderer>.enabled = false;
         renderer.enabled = false;
         
     }
     void Update () {
         
         followerIndex = Random.Range(0, followers.Length); // Give me a random int from followers[]
         spawnRange = Random.Range(0.5f, -0.5f);
         spawnFromPoint = new Vector3(0, spawnRange, 0);
         
         //Make followers spawn on a countdown timer
         // Every time the SpawnRate ticks, the follower can spawn at anytime between this tick,and the next tick.
         
         if (Time.time > nextSpawn && spawnWindowOpen == true) {
             
             spawnWindow = Random.Range(Time.time, Time.time + spawnRate);
             nextSpawnWindow = Time.time + spawnWindow;
             GameObject piClone = Instantiate(followers[followerIndex], transform.position + spawnFromPoint, transform.rotation) as GameObject;
             spawnWindowOpen = false;
             Debug.Log ("***Follower has been spawned***");
         }
         if (Time.time > nextSpawn && spawnWindowOpen == false) {
             nextSpawn = Time.time + spawnRate; // Trigger next spawn
             spawnWindowOpen = true;
             Debug.Log ("***Ready for the next follower***");
             
         }
     }
 }

Any help appreciated.