Frequencies for first 10,000 rows of heart variable in natl1997 dataset :

      Heart |
malformatio |
         ns |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          8        0.08        0.08
          2 |      9,980       99.80       99.88
          9 |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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