low fps in empty scene android

Hi all. I have a problem with fps. I have a scene that has NOTHING in it just a main camera, directional light and a 3dtext that shows number of fps by a script. But when i run it in android it shows me sth between 40 fps and 55 fps and it never goes to 60 fps! thanks the script that shows the number of fps is this:

 using UnityEngine;
 using System.Collections;
 
 public class fps : MonoBehaviour {
 
     public TextMesh myUi;
     //Declare these in your class
     int m_frameCounter = 0;
     float m_timeCounter = 0.0f;
     float m_lastFramerate = 0.0f;
     public float m_refreshTime = 0.5f;
 
 
     void Update()
     {
         myUi.text = m_lastFramerate.ToString ("F2");
         if( m_timeCounter < m_refreshTime )
         {
             m_timeCounter += Time.deltaTime;
             m_frameCounter++;
 
         }
         else
         {
             //This code will break if you set your m_refreshTime to 0, which makes no sense.
             m_lastFramerate = (float)m_frameCounter/m_timeCounter;
             m_frameCounter = 0;
             m_timeCounter = 0.0f;
         }
     }
 }
 

i wonder if anyone can help cause it made me crazy. p.s: I used solid colour for skybox.