Runaway AI

Hello good day guys! I have some i guess, well simple problem.
I cant seem to find how i would make the enemy runway from the player when low in health?
here is the code for the health:
{
public float enemyHealth = 25;
public GameObject DeadPrefab;

    public void TakeDamage(float amnt)
    {
        enemyHealth -= amnt;

        if(enemyHealth <= 0)
        {
            Instantiate(DeadPrefab, transform.position, transform.rotation);
            {
                Destroy(this.gameObject);
            }
        }
        //survived!
        if (enemyHealth <= 20)
        {
            //runawayfunctionhere
        }
    }
}

And Here is for the AI:

	UnityEngine.AI.NavMeshAgent agent;
	public Transform target;
    public float extraRotationSpeed;


    void Start () 
	{
        target = GameObject.FindWithTag("Player").transform;
        agent = GetComponent<UnityEngine.AI.NavMeshAgent> ();
	}

    void Update()
    {
        extraRotation();
        agent.SetDestination(target.position);
    }

    void extraRotation()
    {
        Vector3 lookrotation = agent.steeringTarget - transform.position;
        transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.LookRotation(lookrotation), extraRotationSpeed * Time.deltaTime);

    }

Perhaps something like:

         void Update()
         {
            if (enemyhealth <= 25)
            {
               extraRotation();
            }
             agent.SetDestination(target.position);
         }
     
         void extraRotation()
         {
             Vector3 lookrotation = agent.transform.position - player.transform.position;
             transform.Translate (lookrotation.normalized * extraRotationSpeed * Time.deltaTime);         
         }