Frequencies for impacts variable in vehnit dataset :

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1        0.07        0.07
          1 |         10        0.72        0.79
          2 |      1,279       91.82       92.61
          3 |        103        7.39      100.00
------------+-----------------------------------
      Total |      1,393      100.00

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