Frequencies for first 10,000 rows of cbc variable in nhamcsed2014 dataset :

        CBC |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      6,566       65.66       65.66
        Yes |      3,434       34.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017