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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        895        8.95        8.95
          1 |      6,234       62.34       71.29
          2 |      1,732       17.32       88.61
          3 |        377        3.77       92.38
          9 |         39        0.39       92.77
          . |        723        7.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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