Frequencies for first 10,000 rows of record_9 variable in linkco1991us_num dataset :

Record-Axis |
  Condition |
Code 9 (ICD |
        9th |
  Revision) |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,991       99.91       99.91
       7707 |          1        0.01       99.92
       7721 |          1        0.01       99.93
       7742 |          1        0.01       99.94
       7776 |          1        0.01       99.95
       7863 |          1        0.01       99.96
       7919 |          1        0.01       99.97
       7991 |          1        0.01       99.98
        911 |          1        0.01       99.99
       9955 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015