Frequencies for first 10,000 rows of proc23 variable in nhamcsed1999 dataset :

      other |
  procedure |
 #2 - 3 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,989       99.89       99.89
        371 |          1        0.01       99.90
        389 |          1        0.01       99.91
        395 |          1        0.01       99.92
        399 |          1        0.01       99.93
        451 |          1        0.01       99.94
        838 |          1        0.01       99.95
        893 |          2        0.02       99.97
        919 |          1        0.01       99.98
        978 |          1        0.01       99.99
        990 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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