Frequencies for first 10,000 rows of nseiz variable in natl1990 dataset :

   Seizures |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         13        0.13        0.13
          2 |      9,920       99.20       99.33
          9 |         67        0.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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