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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,270       22.70       22.70
          1 |        547        5.47       28.17
          2 |      1,436       14.36       42.53
          3 |      1,529       15.29       57.82
          4 |      4,076       40.76       98.58
          5 |         40        0.40       98.98
          9 |        102        1.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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