Frequencies for first 10,000 rows of uld_abrup variable in natlterr2006 dataset :

   Abruptio |
   placenta |
        RFP |
714=f_uld_a |
  bruptio U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.07        0.07
          2 |      4,727       47.27       47.34
          9 |      1,541       15.41       62.75
          . |      3,725       37.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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