Frequencies for first 10,000 rows of proc6 variable in namcs1993 dataset :

 service #6 |
  procedure |
   code - 4 |
     digits |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      9,996       99.96       99.96
       8192 |          1        0.01       99.97
       8872 |          1        0.01       99.98
       8879 |          1        0.01       99.99
       9335 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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