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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,122       21.22       21.22
          1 |        584        5.84       27.06
          2 |      1,475       14.75       41.81
          3 |      1,503       15.03       56.84
          4 |      4,083       40.83       97.67
          5 |        131        1.31       98.98
          6 |          1        0.01       98.99
          9 |        101        1.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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