Changing variable in a script of a game object hit with raycast

I have a script that is my gun shooting script (with raycast), and another one that has my enemies health. I want to know how to make it so that when my enemy gets hit with raycast, the variable zHealth goes down for only the zombie hit with raycast. The enemies are all instantiated clones of the same game object.

shootingGunScript

 #pragma strict
 var zHealth = 3;
 var spawnPoint : Transform;
 var muzzleFlash : Renderer;
 var MuzzleLight : Light;
 var Zombiebehaviourscript : Zombiebehaviourscript;
 //var shotSound : AudioClip;
 
 
 function Start () {
 muzzleFlash.enabled = false;
 MuzzleLight.enabled = false;
 
 }
 
 function Update () {
 
 if(Input.GetMouseButtonDown(0)){
 
 var hit : RaycastHit;
 var rayray = Physics.Raycast(spawnPoint.position, spawnPoint.forward, Mathf.Infinity);
 Debug.DrawRay (spawnPoint.position, spawnPoint.forward*10, Color.green);
 Shoot();
 
 if (Physics.Raycast(spawnPoint.position, spawnPoint.forward, hit, Mathf.Infinity)){
 Zombiebehaviourscript.zHealth -= 1;
 }
 
   
 
 }
 
 }
 
 function Shoot (){
 muzzleFlash.renderer.enabled = true;
 MuzzleLight.enabled = true;
 yield WaitForSeconds (0.02);
 muzzleFlash.renderer.enabled = false;
 MuzzleLight.enabled = false;
 }

Zombiebehaviourscript

 #pragma strict
 var zHealth = 3;
 var zspeed = 5;
 var attackTimer = 1;
 var attackRange = 1.5;
 var zdead = false;
 var target : Transform;
 var zTransform : Transform;
 var healthPlayer : healthPlayer;
 var zombie = GameObject;
 
 function Start () {
 
 }
 
 function DestroyThisGameObject()
 {
     Destroy(this.gameObject);
 }
 
 function Update () {
 
 if(zHealth < 1){
 zdead = true;
 }
 if(zdead == true){
 DestroyThisGameObject();
 }
 
 transform.Translate(Vector3.forward*zspeed*Time.deltaTime);
 
 transform.LookAt(target);
 
 //
 ////
 var distance = (target.position - zTransform.position).sqrMagnitude;
 if(distance < attackRange && Time.time > attackTimer){
 healthPlayer.totalHealth -= healthPlayer.damage;
 attackTimer = Time.time + 2;
 Debug.Log ("Hit");
 }
 ////
 //
 
 
 }
 
 
 
 
 
 function FixedUpdate(){
 
 
 
 }