Frequencies for first 10,000 rows of cbc variable in nhamcsopd2010 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      8,873       88.73       88.73
        yes |      1,127       11.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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