Frequencies for first 10,000 rows of proc6 variable in namcs2011 dataset :

Procedure 6 |
  - 4 digit |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      9,968       99.68       99.68
       4946 |          1        0.01       99.69
       8619 |          1        0.01       99.70
       8913 |         16        0.16       99.86
       8929 |          2        0.02       99.88
       8938 |          4        0.04       99.92
       8959 |          4        0.04       99.96
       9201 |          2        0.02       99.98
       9509 |          1        0.01       99.99
       9547 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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