Frequencies for inj_sev variable in person dataset :

     INJURY |
   SEVERITY |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        252       23.40       23.40
          2 |        177       16.43       39.83
          3 |        153       14.21       54.04
          4 |        495       45.96      100.00
------------+-----------------------------------
      Total |      1,077      100.00

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