Frequencies for first 10,000 rows of proc63d variable in namcs2014 dataset :

   Write-in |
  procedure |
   code - 3 |
      digit |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      9,996       99.96       99.96
        940 |          2        0.02       99.98
        950 |          1        0.01       99.99
        994 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017