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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        533        5.33        5.33
          1 |      6,238       62.38       67.71
          2 |      2,623       26.23       93.94
          3 |        527        5.27       99.21
          9 |         79        0.79      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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