Frequencies for first 10,000 rows of cig_0 variable in natl2014 dataset :

 Cigarettes |
     Before |
  Pregnancy |
      00-97 |
  Number of |
 cigarettes |
      daily |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,142       81.42       81.42
          1 |         47        0.47       81.89
          2 |         71        0.71       82.60
          3 |         76        0.76       83.36
          4 |         80        0.80       84.16
          5 |        182        1.82       85.98
          6 |         69        0.69       86.67
          7 |         48        0.48       87.15
          8 |         44        0.44       87.59
          9 |          3        0.03       87.62
         10 |        375        3.75       91.37
         11 |          3        0.03       91.40
         12 |         15        0.15       91.55
         13 |          6        0.06       91.61
         14 |          2        0.02       91.63
         15 |         53        0.53       92.16
         16 |          2        0.02       92.18
         18 |          2        0.02       92.20
         20 |        348        3.48       95.68
         21 |          1        0.01       95.69
         24 |          5        0.05       95.74
         25 |          3        0.03       95.77
         27 |          1        0.01       95.78
         30 |         15        0.15       95.93
         32 |          1        0.01       95.94
         36 |          1        0.01       95.95
         40 |         43        0.43       96.38
         41 |          1        0.01       96.39
         45 |          2        0.02       96.41
         46 |          1        0.01       96.42
         48 |          1        0.01       96.43
         50 |          1        0.01       96.44
         60 |         17        0.17       96.61
         80 |         17        0.17       96.78
         99 |        322        3.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016