Frequencies for first 10,000 rows of f_ca_heart variable in natl2013 dataset :

   Cyanotic |
 Congenital |
      Heart |
    Disease |
(ca_cchd) R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          2        0.02        0.02
          1 |      9,998       99.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015