Frequencies for impacts variable in vehnit dataset :

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         12        0.81        0.81
          1 |         12        0.81        1.62
          2 |      1,362       91.96       93.59
          3 |         95        6.41      100.00
------------+-----------------------------------
      Total |      1,481      100.00

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