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

   Seizures |
     during |
      labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |      9,963       99.63       99.64
          9 |         36        0.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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