Frequencies for first 10,000 rows of proc63d variable in namcs1994 dataset :

 service #6 |
  procedure |
   code - 3 |
     digits |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,994       99.94       99.94
        501 |          1        0.01       99.95
        873 |          1        0.01       99.96
        876 |          1        0.01       99.97
        893 |          1        0.01       99.98
        895 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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