Frequencies for a8 variable in midrvacc dataset :

         a8 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        291       62.72       62.72
          1 |          1        0.22       62.93
          2 |          4        0.86       63.79
          3 |          5        1.08       64.87
          4 |          3        0.65       65.52
          5 |          4        0.86       66.38
          6 |          4        0.86       67.24
          7 |          4        0.86       68.10
          8 |          8        1.72       69.83
          9 |          5        1.08       70.91
         10 |          6        1.29       72.20
         11 |          6        1.29       73.49
         12 |          9        1.94       75.43
         13 |          6        1.29       76.72
         14 |          8        1.72       78.45
         15 |         13        2.80       81.25
         16 |          5        1.08       82.33
         17 |          6        1.29       83.62
         18 |          6        1.29       84.91
         19 |         10        2.16       87.07
         20 |          8        1.72       88.79
         21 |          5        1.08       89.87
         22 |          7        1.51       91.38
         23 |          4        0.86       92.24
         24 |          2        0.43       92.67
         25 |          3        0.65       93.32
         26 |          5        1.08       94.40
         27 |          3        0.65       95.04
         28 |          7        1.51       96.55
         29 |          3        0.65       97.20
         30 |          2        0.43       97.63
         31 |          3        0.65       98.28
         32 |          2        0.43       98.71
         34 |          1        0.22       98.92
         36 |          2        0.43       99.35
         37 |          1        0.22       99.57
         38 |          1        0.22       99.78
         39 |          1        0.22      100.00
------------+-----------------------------------
      Total |        464      100.00

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