Frequencies for first 10,000 rows of heart variable in natl1989 dataset :

      Heart |
malformatio |
         ns |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.07        0.07
          2 |      9,756       97.56       97.63
          9 |        237        2.37      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016