increamenting speed periodically

thanks for the help i figured out how to do it. below is the script.

 using UnityEngine;
 using System.Collections;
 
 public class enemy_script : $$anonymous$$onoBehaviour {
 
     public float enemySpeed = 5;
 
 void Start () {

         InvokeRepeating("gameTimer",60,60);
     }
 
 void gameTimer()
     {
         print(enemySpeed);
         enemySpeed += 2;
     }