Frequencies for first 10,000 rows of biopsy variable in nhamcsopd2009 dataset :

     biopsy |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,842       98.42       98.42
        yes |        158        1.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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