Frequencies for first 10,000 rows of radther variable in nhamcsopd2008 dataset :

  radiation |
    therapy |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,982       99.82       99.82
        yes |         18        0.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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