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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        864        8.64        8.64
          1 |      6,294       62.94       71.58
          2 |      1,685       16.85       88.43
          3 |        357        3.57       92.00
          9 |          2        0.02       92.02
          . |        798        7.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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