Frequencies for first 10,000 rows of heart variable in natl1999 dataset :

      Heart |
malformatio |
         ns |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         13        0.13        0.13
          2 |      9,987       99.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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