Frequencies for first 10,000 rows of proc2 variable in nhamcsed1993 dataset :

      other |
  procedure |
     #2 - 4 |
      digit |      Freq.     Percent        Cum.
------------+-----------------------------------
       0000 |      9,917       99.17       99.17
       7534 |          6        0.06       99.23
       8926 |          5        0.05       99.28
       8934 |          1        0.01       99.29
       8938 |          5        0.05       99.34
       8939 |         18        0.18       99.52
       8954 |          1        0.01       99.53
       8959 |         13        0.13       99.66
       8965 |          1        0.01       99.67
       9059 |          8        0.08       99.75
       9146 |          1        0.01       99.76
       9191 |          4        0.04       99.80
       9339 |          1        0.01       99.81
       9399 |          2        0.02       99.83
       9449 |          1        0.01       99.84
       9670 |          1        0.01       99.85
       9729 |          1        0.01       99.86
       9962 |          1        0.01       99.87
       9999 |         13        0.13      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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