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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        812        8.12        8.12
          1 |      5,355       53.55       61.67
          2 |      2,608       26.08       87.75
          3 |        478        4.78       92.53
          9 |        119        1.19       93.72
          . |        628        6.28      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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