Frequencies for first 10,000 rows of xray variable in nhamcsopd2011 dataset :

      X-ray |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,268       92.68       92.68
        Yes |        732        7.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016