Frequencies for first 10,000 rows of cbc variable in nhamcsed2002 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,968       69.68       69.68
          1 |      3,032       30.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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