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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        879        8.79        8.79
          1 |      6,211       62.11       70.90
          2 |      1,659       16.59       87.49
          3 |        441        4.41       91.90
          9 |         85        0.85       92.75
          . |        725        7.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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