Frequencies for first 10,000 rows of inj_sev variable in person dataset :

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,169       21.69       21.69
          1 |        549        5.49       27.18
          2 |      1,369       13.69       40.87
          3 |      1,712       17.12       57.99
          4 |      4,028       40.28       98.27
          5 |         85        0.85       99.12
          9 |         88        0.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016