Frequencies for first 10,000 rows of distress variable in natl1992 dataset :

      Fetal |
   distress |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        294        2.94        2.94
          2 |      9,669       96.69       99.63
          8 |          1        0.01       99.64
          9 |         36        0.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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