Frequencies for first 10,000 rows of cig_0 variable in natl2013 dataset :

 Cigarettes |
     Before |
  Pregnancy |
575=f_tobac |
        o R |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,153       81.53       81.53
          1 |         39        0.39       81.92
          2 |         66        0.66       82.58
          3 |        111        1.11       83.69
          4 |         71        0.71       84.40
          5 |        170        1.70       86.10
          6 |         73        0.73       86.83
          7 |         52        0.52       87.35
          8 |         50        0.50       87.85
          9 |          9        0.09       87.94
         10 |        368        3.68       91.62
         11 |          5        0.05       91.67
         12 |         30        0.30       91.97
         13 |          2        0.02       91.99
         14 |          2        0.02       92.01
         15 |         40        0.40       92.41
         16 |          3        0.03       92.44
         17 |          1        0.01       92.45
         18 |          3        0.03       92.48
         20 |        350        3.50       95.98
         21 |          2        0.02       96.00
         22 |          1        0.01       96.01
         23 |          2        0.02       96.03
         24 |          3        0.03       96.06
         25 |          5        0.05       96.11
         29 |          1        0.01       96.12
         30 |         23        0.23       96.35
         40 |         43        0.43       96.78
         45 |          2        0.02       96.80
         50 |          2        0.02       96.82
         60 |         13        0.13       96.95
         65 |          1        0.01       96.96
         80 |         34        0.34       97.30
         90 |          1        0.01       97.31
         99 |        269        2.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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