Frequencies for first 10,000 rows of tobacco variable in natlterr2002 dataset :

Tobacco Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        110        1.10        1.10
          2 |      9,875       98.75       99.85
          9 |         15        0.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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