Frequencies for first 10,000 rows of tobacco variable in natl1990 dataset :

Tobacco Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,592       15.92       15.92
          2 |      8,344       83.44       99.36
          9 |         64        0.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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