How to make enemy speed up

I made a gravity runner game but I want the enemy to speed up in the beginning because he starts outside of the screen, any suggestions? Here is my code:

 using UnityEngine;
 using System.Collections;
 
 public class Enemy : MonoBehaviour {
     public Transform target;
     public int MoveSpeed = 8;
     public int MaxDist = 2;
     public int MinDist = 1;
     private Zwaartekracht vijand;
 
 
     // Use this for initialization
     void Start () {
     
     }
     // Update is called once per frame
     void Update () {
         transform.LookAt(target);
         
         if(Vector3.Distance(transform.position,target.position) >= MinDist && Zwaartekracht.state == 1){
             
             transform.position += transform.forward * MoveSpeed * Time.deltaTime;
             
             
             
             /*if(Vector3.Distance(transform.position,target.position) <= MaxDist)
             {
                 //Here Call any function U want Like Shoot at here or something
             } */
             
         }
     }
 }