Frequencies for first 10,000 rows of impacts variable in vehicle dataset :

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        611        6.11        6.11
          1 |      7,088       70.88       76.99
          2 |      1,759       17.59       94.58
          3 |        437        4.37       98.95
          9 |        105        1.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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