Frequencies for first 10,000 rows of cbc variable in nhamcsed2003 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      6,940       69.40       69.40
        yes |      3,060       30.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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