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

     Injury |
   Severity |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,095       20.95       20.95
          1 |        620        6.20       27.15
          2 |      1,342       13.42       40.57
          3 |      1,742       17.42       57.99
          4 |      4,075       40.75       98.74
          5 |         37        0.37       99.11
          9 |         89        0.89      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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