Frequencies for first 10,000 rows of exmwi23d variable in namcs2004 dataset :

       exam |
write-in #2 |
  - 3 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,622       96.22       96.22
        833 |          1        0.01       96.23
        891 |          6        0.06       96.29
        892 |         47        0.47       96.76
        893 |        304        3.04       99.80
        897 |          1        0.01       99.81
        941 |          1        0.01       99.82
        950 |         16        0.16       99.98
        954 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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