Frequencies for first 10,000 rows of alcohol variable in natlterr1995 dataset :

Alcohol Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         20        0.20        0.20
          2 |      9,977       99.77       99.97
          9 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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