Frequencies for first 10,000 rows of biopsy variable in nhamcsopd2001 dataset :

     biopsy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,869       98.69       98.69
          1 |        131        1.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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