Frequencies for first 10,000 rows of outcome variable in natl1978 dataset :

 Outcome of |
       Last |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,860       38.60       38.60
          1 |      5,029       50.29       88.89
          2 |        750        7.50       96.39
          3 |        361        3.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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