Frequencies for first 10,000 rows of alcohol variable in natl1997 dataset :

Alcohol Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         48        0.48        0.48
          2 |      9,922       99.22       99.70
          9 |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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