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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        884        8.84        8.84
          1 |      6,248       62.48       71.32
          2 |      1,710       17.10       88.42
          3 |        346        3.46       91.88
          9 |         15        0.15       92.03
          . |        797        7.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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