Frequencies for a7 variable in midrvacc dataset :

         a7 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        287       61.85       61.85
          1 |          1        0.22       62.07
          2 |          5        1.08       63.15
          3 |          3        0.65       63.79
          4 |          4        0.86       64.66
          5 |          3        0.65       65.30
          6 |          2        0.43       65.73
          7 |          4        0.86       66.59
          8 |          6        1.29       67.89
          9 |          5        1.08       68.97
         10 |          6        1.29       70.26
         11 |          6        1.29       71.55
         12 |          8        1.72       73.28
         13 |          4        0.86       74.14
         14 |         10        2.16       76.29
         15 |         13        2.80       79.09
         16 |          7        1.51       80.60
         17 |          9        1.94       82.54
         18 |          2        0.43       82.97
         19 |         12        2.59       85.56
         20 |         10        2.16       87.72
         21 |          4        0.86       88.58
         22 |         10        2.16       90.73
         23 |          4        0.86       91.59
         24 |          3        0.65       92.24
         25 |          6        1.29       93.53
         26 |          4        0.86       94.40
         27 |          4        0.86       95.26
         28 |          8        1.72       96.98
         29 |          4        0.86       97.84
         30 |          3        0.65       98.49
         31 |          2        0.43       98.92
         32 |          1        0.22       99.14
         34 |          1        0.22       99.35
         36 |          1        0.22       99.57
         39 |          2        0.43      100.00
------------+-----------------------------------
      Total |        464      100.00

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