Frequencies for first 10,000 rows of cig_0 variable in natl2011 dataset :

 Cigarettes |
     Before |
  Pregnancy |
575=f_tobac |
        o R |      Freq.     Percent        Cum.
------------+-----------------------------------
          . |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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