Frequencies for first 10,000 rows of outcome variable in natl1987 dataset :

 Outcome of |
       Last |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,838       38.38       38.38
          1 |      4,943       49.43       87.81
          2 |      1,118       11.18       98.99
          3 |        101        1.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016