Frequencies for first 10,000 rows of seizure variable in natl1998 dataset :

   Seizures |
     during |
      labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      9,997       99.97       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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