Frequencies for first 10,000 rows of seizure variable in linkco1991us_num dataset :

   Seizures |
     during |
      labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         12        0.12        0.12
          2 |      9,781       97.81       97.93
          9 |        207        2.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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