Frequencies for first 10,000 rows of a4 variable in midrvacc dataset :

         a4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,591       65.91       65.91
          1 |         55        0.55       66.46
          2 |         67        0.67       67.13
          3 |         52        0.52       67.65
          4 |         68        0.68       68.33
          5 |         66        0.66       68.99
          6 |         72        0.72       69.71
          7 |        100        1.00       70.71
          8 |         95        0.95       71.66
          9 |         89        0.89       72.55
         10 |        103        1.03       73.58
         11 |        161        1.61       75.19
         12 |        133        1.33       76.52
         13 |        164        1.64       78.16
         14 |        174        1.74       79.90
         15 |        163        1.63       81.53
         16 |        157        1.57       83.10
         17 |        165        1.65       84.75
         18 |        172        1.72       86.47
         19 |        160        1.60       88.07
         20 |        156        1.56       89.63
         21 |        147        1.47       91.10
         22 |        136        1.36       92.46
         23 |        105        1.05       93.51
         24 |        112        1.12       94.63
         25 |        104        1.04       95.67
         26 |         87        0.87       96.54
         27 |         62        0.62       97.16
         28 |         54        0.54       97.70
         29 |         37        0.37       98.07
         30 |         45        0.45       98.52
         31 |         30        0.30       98.82
         32 |         16        0.16       98.98
         33 |         23        0.23       99.21
         34 |         15        0.15       99.36
         35 |         10        0.10       99.46
         36 |         13        0.13       99.59
         37 |          8        0.08       99.67
         38 |          4        0.04       99.71
         39 |          2        0.02       99.73
         40 |          8        0.08       99.81
         41 |          2        0.02       99.83
         42 |          2        0.02       99.85
         43 |          2        0.02       99.87
         44 |          4        0.04       99.91
         48 |          2        0.02       99.93
         50 |          1        0.01       99.94
         59 |          1        0.01       99.95
         67 |          1        0.01       99.96
         68 |          1        0.01       99.97
         79 |          1        0.01       99.98
         94 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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