Frequencies for first 10,000 rows of urf_eclam variable in natlterr2010 dataset :

  Eclampsia |
        RFP |
690=f_urf_e |
  clamp U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         18        0.18        0.18
          2 |      7,953       79.53       79.71
          9 |      2,029       20.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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