Unity iPhone Touch Counter

I'm trying to create a counter to work on iPhone using Touch events on a primitive cube GameObject. I only want it to increment once per touch. As it is now, it reads the touch in milliseconds, so the update function it may Log 3 to 5 counts per update. Is there a "MonoBehaivor.OnMouseDown" for iOS Touches?

// attach the script to a primitive, then when tapped on iPhone it should increment a single integer per touch to the debug.log //

 private var pickNum = 0;
 
 function Update(){
 if (Input.touchCount > 0){ 
 
 
     var touchPosition:Vector2 = Input.GetTouch(0).position;
     var ray : Ray = Camera.main.ScreenPointToRay (touchPosition);        
     var hit : RaycastHit;
     
      if (collider.Raycast (ray, hit, 20.0)) {
          transform.Rotate(0,0,10);
  
            pickNum = Input.touchCount + 1;
         Debug.Log("Screen Touched " + pickNum + " times");}      
         }
     }
 }