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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        692        6.92        6.92
          1 |      6,931       69.31       76.23
          2 |      1,800       18.00       94.23
          3 |        519        5.19       99.42
          9 |         58        0.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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