Frequencies for impacts variable in vehnit dataset :

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1        0.09        0.09
          1 |         12        1.08        1.16
          2 |      1,016       91.04       92.20
          3 |         87        7.80      100.00
------------+-----------------------------------
      Total |      1,116      100.00

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