Frequencies for first 10,000 rows of outcome variable in natl1981 dataset :

 Outcome of |
       Last |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,822       38.22       38.22
          1 |      4,782       47.82       86.04
          2 |        981        9.81       95.85
          3 |        415        4.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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