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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,057       20.57       20.57
          1 |        717        7.17       27.74
          2 |      1,333       13.33       41.07
          3 |      1,693       16.93       58.00
          4 |      4,060       40.60       98.60
          5 |         24        0.24       98.84
          9 |        116        1.16      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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