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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,103       11.03       11.03
          1 |      6,045       60.45       71.48
          2 |      1,662       16.62       88.10
          3 |        295        2.95       91.05
          9 |         20        0.20       91.25
          . |        875        8.75      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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