Frequencies for first 10,000 rows of outcome variable in natl1988 dataset :

 Outcome of |
       Last |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,783       37.83       37.83
          1 |      4,743       47.43       85.26
          2 |      1,014       10.14       95.40
          3 |        460        4.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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