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

     Biopsy |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,844       98.44       98.44
        Yes |        156        1.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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