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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        563        5.63        5.63
          1 |      6,241       62.41       68.04
          2 |      2,592       25.92       93.96
          3 |        517        5.17       99.13
          9 |         87        0.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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