Frequencies for first 10,000 rows of tobacco variable in linkco1991us_num dataset :

Tobacco Use |
     During |
  Pregnancy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,198       11.98       11.98
          2 |      4,194       41.94       53.92
          9 |      4,608       46.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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