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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        302        3.02        3.02
          1 |      7,244       72.44       75.46
          2 |      2,034       20.34       95.80
          3 |        397        3.97       99.77
          9 |         23        0.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016