Plotting average of a standard deviation (please refer Query Below)

[#1]

I need to plot following

Avg( Stdev (Peak WL  Group by Wafer Id) ) Group by Base Growth

Here Base_Growth = LEFT (Wafer_id,11) 

Please refer below query

SELECT LEFT (a.Wafer_id,11)  Base_Growth  , AVG(stdev_PL) Avg_Stdev_PL

FROM

(

  SELECT Wafer_id, stdev((peak_lambda))stdev_PL

  FROM dbo.f_LED_Reactor_PL_Data  WITH (NOLOCK)

  GROUP BY Wafer_id

) A

GROUP BY LEFT (a.Wafer_id,11)

Please any input will be helpful.

Thanks,

Nithin