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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        692        6.92        6.92
          1 |      6,922       69.22       76.14
          2 |      1,858       18.58       94.72
          3 |        478        4.78       99.50
          9 |         50        0.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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