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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        546        5.46        5.46
          1 |      6,506       65.06       70.52
          2 |      1,776       17.76       88.28
          3 |        253        2.53       90.81
          9 |         41        0.41       91.22
          . |        878        8.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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