Get distance player has run wrong values

I’m having some troubles with my unity game. If my player collides with an object the game over scene is shown, and there I wanna display the distance the player has run.

That's my code

 function Update () {
 var controller : CharacterController = GetComponent(CharacterController);
   
 if (controller.isGrounded) {
   transform.Translate(0, 0, speedForward * Time.deltaTime); 
   run = transform.localPosition.z; 
   moveDirection = Vector3(Input.GetAxis("Horizontal"), 0, 0);
   moveDirection = transform.TransformDirection(moveDirection);
   moveDirection *= speedHorizontal;
    }

But it doesn’t return the right result (sometimes 298, sometimes 299 ). These values are when I let the player run automatically without moving left or right. When I move left and right the result is always different from the results when i only run forward differently (e.g. it displays as result 294 or 293). Could somebody tell me what’s wrong with my code?