Frequencies for first 10,000 rows of seizure variable in natl1991 dataset :

   Seizures |
     during |
      labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          8        0.08        0.08
          2 |      9,962       99.62       99.70
          9 |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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