Frequencies for first 10,000 rows of tobacco variable in natl1996 dataset :

Tobacco Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,311       13.11       13.11
          2 |      8,655       86.55       99.66
          9 |         34        0.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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