Frequencies for first 10,000 rows of tobacco variable in natl1993 dataset :

Tobacco Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,485       14.85       14.85
          2 |      8,507       85.07       99.92
          9 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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