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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        471        4.71        4.71
          1 |      6,469       64.69       69.40
          2 |      2,483       24.83       94.23
          3 |        550        5.50       99.73
          9 |         27        0.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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