Frequencies for first 10,000 rows of cbc variable in nhamcsopd2009 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,679       86.79       86.79
        yes |      1,321       13.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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