Damage function affecting all instances of object

I am trying to get a damage script working, as it stands I have a bullet that calls the “takeDamage” function on the object which it collides with. The trouble is that calling the function of any single instance of the object calls all of the instances and reduces the “health” variable of all instances of the object.

Bullet script:

public class bulletStats : MonoBehaviour {
    public float damage;

    private void OnTriggerEnter(Collider other)
        if (other.transform.tag == "enemy")

Health script:

public class enemyHealth : MonoBehaviour {
    private float health;
	// Use this for initialization
	void Start () {

    //damage the asteroid
    public void takeDamage(float damage)
        health = health - damage;

did you ever figure out the solution to this problem? I’m running into a similar issue myself