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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,249       12.49       12.49
          1 |      5,283       52.83       65.32
          2 |      2,285       22.85       88.17
          3 |        443        4.43       92.60
          9 |         91        0.91       93.51
          . |        649        6.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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