Bullet is shooting every frame? How do I limit it to 1 bullet per second?

I'm trying to change a script to shoot 1 bullet per second on mouse being held. The void update and IEnumerator was added by me , the fire() function is the script..

 void Update(){

     if (Input.GetMouseButton (0)) {

         StartCoroutine (FireShot ());
     }

 }
     
 IEnumerator FireShot() {

     Fire ();
     yield return new WaitForSeconds (1);
 }


 public void  Fire()
 {
         Vector3 mousePoint = Camera.main.ScreenToWorldPoint (Input.mousePosition);
         transform.up = Vector3.Normalize (mousePoint + Vector3.forward * 10 - transform.position);
         if (PlayerPrefs.GetInt ("gold", 200) < _levelGun && _tenlua == false)
             popUp.SetActive (true);
         else {
             if (PlayerPrefs.GetInt ("gold", 200) >= _levelGun && _checkfire && _tenlua == false) {
             
                 _ani.Play ("Fire", 0, 0);
                 AudioControl.Instance.shoot ();
                 GameObject _bullet = (GameObject)Instantiate (Bullet);
                 _bullet.transform.position = transform.position + transform.up * 0.5f;
                 _bullet.GetComponent<BulletControl> ().InitBullet (_levelGun, transform, new Vector2 (mousePoint.x, mousePoint.y));

                 UiTextSpawmControl.Instance.MinusGold (_levelGun);

             }
         }
         if (_tenlua && _checkfire) {
             _tenlua = false;
             tenlua.transform.up = Vector3.Normalize (mousePoint + Vector3.forward * 10 - tenlua.transform.position);
             _checkfire = false;
             LeanTween.move (tenlua, new Vector3 (mousePoint.x, mousePoint.y, 0), 0.2f * (Vector2.Distance (mousePoint, tenlua.transform.position))).setOnComplete (() => {
                 RaycastHit2D[] fish = Physics2D.CircleCastAll (new Vector3 (tenlua.transform.position.x, tenlua.transform.position.y, 0), 2, Vector3.zero);
                 AudioControl.Instance.boom ();
                 for (int i = 0; i < fish.Length; i++) {
                     if (fish [i].collider.tag == "fish")
                         fish [i].collider.gameObject.GetComponent<FishControl> ().hitDame (1000, gameObject);
                 }
                 GameObject boom = (GameObject)Instantiate (_effboom, tenlua.transform.position + tenlua.transform.up * 0.5f, Quaternion.identity);
                 Destroy (boom, 1.5f);
                 tenlua.SetActive (false);
                 GetComponent<SpriteRenderer> ().enabled = true;
                 transform.up = Vector3.up;
                 transform.localScale = Vector3.zero;
                 LeanTween.scale (gameObject, new Vector3 (1, 1, 1), 0.5f).setEase (LeanTweenType.easeOutBack).setOnComplete (() => {
                     _checkfire = true;
                 });
             });
         }
 }