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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,243       22.43       22.43
          1 |        547        5.47       27.90
          2 |      1,313       13.13       41.03
          3 |      1,573       15.73       56.76
          4 |      4,194       41.94       98.70
          5 |          9        0.09       98.79
          9 |        121        1.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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