Frequencies for first 10,000 rows of cig_0 variable in natlterr2012 dataset :

 Cigarettes |
     Before |
  Pregnancy |
575=f_tobac |
        o R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,727       77.27       77.27
          1 |         14        0.14       77.41
          2 |         29        0.29       77.70
          3 |         25        0.25       77.95
          4 |         21        0.21       78.16
          5 |         37        0.37       78.53
          6 |         21        0.21       78.74
          7 |          5        0.05       78.79
          8 |          7        0.07       78.86
          9 |          2        0.02       78.88
         10 |         97        0.97       79.85
         12 |          3        0.03       79.88
         13 |          1        0.01       79.89
         15 |          8        0.08       79.97
         20 |        114        1.14       81.11
         25 |          1        0.01       81.12
         30 |          1        0.01       81.13
         40 |          9        0.09       81.22
         50 |          1        0.01       81.23
         60 |          1        0.01       81.24
         80 |          3        0.03       81.27
         99 |        710        7.10       88.37
          . |      1,163       11.63      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 5 May 2016