Frequencies for first 10,000 rows of usetobac variable in namcs2010 dataset :

tobacco use |      Freq.     Percent        Cum.
------------+-----------------------------------
      blank |        321        3.21        3.21
    unknown |      2,112       21.12       24.33
not current |      6,624       66.24       90.57
    current |        943        9.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016