Frequencies for first 10,000 rows of cbc variable in nhamcsed2000 dataset :

        cbc |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,401       74.01       74.01
          1 |      2,599       25.99      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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