Frequencies for first 10,000 rows of procnone variable in nhamcsed1993 dataset :

 procedures |
     - none |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,165       41.65       41.65
          1 |      5,835       58.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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