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

   Seizures |
     during |
      labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          3        0.03        0.03
          2 |      9,772       97.72       97.75
          9 |        225        2.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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