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

     Biopsy |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,912       99.12       99.12
        Yes |         88        0.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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