Frequencies for first 10,000 rows of exmwi23d variable in namcs2001 dataset :

       exam |
write-in #2 |
  - 3 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,647       96.47       96.47
        162 |          2        0.02       96.49
        891 |          6        0.06       96.55
        892 |        104        1.04       97.59
        893 |        229        2.29       99.88
        941 |          3        0.03       99.91
        950 |          4        0.04       99.95
        954 |          2        0.02       99.97
        999 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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