Frequencies for first 10,000 rows of cbc variable in nhamcsed2009 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,383       63.83       63.83
          1 |      3,617       36.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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