Frequencies for first 10,000 rows of urf_eclam variable in natl2012 dataset :

  Eclampsia |
        RFP |
690=f_urf_e |
  clamp U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         43        0.43        0.43
          2 |      7,517       75.17       75.60
          9 |      2,440       24.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 5 May 2016