Frequencies for first 10,000 rows of urf_eclam variable in natl2015 dataset :

Eclampsia 1 |
        Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         96        0.96        0.96
          2 |      9,796       97.96       98.92
          9 |        108        1.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016