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

   Seizures |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         21        0.21        0.21
          2 |      9,950       99.50       99.71
          9 |         29        0.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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