Frequencies for first 10,000 rows of radther variable in namcs2011 dataset :

  Radiation |
    therapy |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,997       99.97       99.97
        Yes |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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