Frequencies for first 10,000 rows of cbc variable in namcs2011 dataset :

        CBC |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,639       86.39       86.39
        Yes |      1,361       13.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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