Frequencies for first 10,000 rows of distress variable in natl1996 dataset :

      Fetal |
   distress |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        407        4.07        4.07
          2 |      9,546       95.46       99.53
          8 |          1        0.01       99.54
          9 |         46        0.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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