Thumb ring and index finger
There is nothing obviously wrong with your handlebar setup. As long the shift and brake levers are easily accessible and you don't have to rotate your wrists or shift your hand laterally along the bar to reach them everything is OK 

Maybe I'd consider moving the levers slightly outwards (and I note there is a slight difference in position, the right hand one is slightly more inboard.  

Numb hands are a common problem. You don't have to ride with your fingers on the levers all the time. Try moving you hands around the bars and bar ends and flexing your fingers from time to time.