Frequencies for first 10,000 rows of examwi2 variable in namcs2004 dataset :

       exam |
write-in #2 |
  - 4 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      9,622       96.22       96.22
       8339 |          1        0.01       96.23
       8913 |          3        0.03       96.26
       8915 |          3        0.03       96.29
       8924 |          5        0.05       96.34
       8926 |         42        0.42       96.76
       8931 |          2        0.02       96.78
       8934 |         40        0.40       97.18
       8936 |         21        0.21       97.39
       8939 |        241        2.41       99.80
       897- |          1        0.01       99.81
       9419 |          1        0.01       99.82
       9509 |         16        0.16       99.98
       9547 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016