Unity mobile delta position not working as expected

Hey Guys,

I want that a certain action triggers when I dragged my finger across 10% of the screen's width. So what I do is like 0.1*Screen.Width and cumulate the position via the first touch like, Input.GetTouch(0).deltaPosition. And when my delaPosition.x > Screen.Width*0.1, I trigger my thing. But it seems like it take about 45-50% of the screen to get to actually 10% of the screen's width. Any ideas ?

 // Touch Screen (mobile) support
             if (Input.touchCount > 0)
             {
                 var touch = Input.GetTouch (0);
                 mCumulatedDelta += touch.deltaPosition;
                 Debug.Log("INCREMENT : "+mCumulatedDelta);
             } 
             else
             {
                 Debug.Log("RESET");
                 mCumulatedDelta = Vector2.zero;
             }
 
         if (mCumulatedDelta.y < mMaxTolerableYDeviation)
         {
             if (mCumulatedDelta.x >= mMinRequiredXDeviation)
             {
                 Debug.Log("CUMULATED DELTA : "+mCumulatedDelta);
                 if (OnSwipeRight != null)
                     OnSwipeRight(mCumulatedDelta.x);
 
                 mCumulatedDelta = Vector2.zero;
                 mLastMousePosition = Vector2.zero;
                 mReadMouse = false;
             }
             else if (mCumulatedDelta.x <= -mMinRequiredXDeviation)
             {
                 Debug.Log("CUMULATED DELTA : "+mCumulatedDelta);
                 if (OnSwipeLeft != null)
                     OnSwipeLeft(mCumulatedDelta.x);
 
                 mCumulatedDelta = Vector2.zero;
                 mLastMousePosition = Vector2.zero;
                 mReadMouse = false;
             }
         }

Thanks a lot.