Frequencies for first 10,000 rows of urf_eclam variable in natl2007 dataset :

  Eclampsia |
        RFP |
690=f_urf_e |
  clamp U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         23        0.23        0.23
          2 |      9,339       93.39       93.62
          9 |        638        6.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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