Frequencies for first 10,000 rows of cbc variable in nhamcsed2005 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      6,282       62.82       62.82
        yes |      3,718       37.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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