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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        866        8.66        8.66
          1 |      5,617       56.17       64.83
          2 |      2,331       23.31       88.14
          3 |        498        4.98       93.12
          9 |         23        0.23       93.35
          . |        665        6.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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