Frequencies for first 10,000 rows of cbc variable in nhamcsopd2011 dataset :

        CBC |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,607       86.07       86.07
        Yes |      1,393       13.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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