Frequencies for first 10,000 rows of uld_prolg variable in natlterr2003 dataset :

  Prolonged |
    Labor U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         11        0.11        0.11
          2 |      9,963       99.63       99.74
          8 |         23        0.23       99.97
          9 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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