Frequencies for first 10,000 rows of cbc variable in nhamcsed2011 dataset :

        CBC |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      6,132       61.32       61.32
        Yes |      3,868       38.68      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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