Frequencies for first 10,000 rows of exmwi23d variable in namcs2003 dataset :

       exam |
write-in #2 |
  - 3 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,636       96.36       96.36
        493 |          1        0.01       96.37
        891 |          6        0.06       96.43
        892 |         44        0.44       96.87
        893 |        258        2.58       99.45
        913 |          1        0.01       99.46
        941 |         11        0.11       99.57
        950 |         41        0.41       99.98
        999 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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