Frequencies for a6 variable in midrvacc dataset :

         a6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        275       59.27       59.27
          1 |          1        0.22       59.48
          2 |          5        1.08       60.56
          3 |          5        1.08       61.64
          4 |          4        0.86       62.50
          5 |          2        0.43       62.93
          6 |          2        0.43       63.36
          7 |          2        0.43       63.79
          8 |          9        1.94       65.73
          9 |          6        1.29       67.03
         10 |          8        1.72       68.75
         11 |          9        1.94       70.69
         12 |         14        3.02       73.71
         13 |          5        1.08       74.78
         14 |         10        2.16       76.94
         15 |         13        2.80       79.74
         16 |          9        1.94       81.68
         17 |          9        1.94       83.62
         18 |          6        1.29       84.91
         19 |         11        2.37       87.28
         20 |          7        1.51       88.79
         21 |          3        0.65       89.44
         22 |          8        1.72       91.16
         23 |          4        0.86       92.03
         24 |          2        0.43       92.46
         25 |          4        0.86       93.32
         26 |          4        0.86       94.18
         27 |          3        0.65       94.83
         28 |          8        1.72       96.55
         29 |          3        0.65       97.20
         30 |          1        0.22       97.41
         31 |          3        0.65       98.06
         32 |          2        0.43       98.49
         34 |          2        0.43       98.92
         36 |          1        0.22       99.14
         37 |          1        0.22       99.35
         38 |          1        0.22       99.57
         39 |          1        0.22       99.78
         46 |          1        0.22      100.00
------------+-----------------------------------
      Total |        464      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016