Frequencies for first 10,000 rows of cbc variable in nhamcsed2015 dataset :

        CBC |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      6,408       64.08       64.08
        Yes |      3,592       35.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017