Frequencies for first 10,000 rows of proc7r variable in namcs2013 dataset :

    Numeric |
 version of |
   write-in |
  procedure |
       code |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      9,996       99.96       99.96
       1341 |          1        0.01       99.97
       1474 |          1        0.01       99.98
       5794 |          1        0.01       99.99
       7162 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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