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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        852        8.52        8.52
          1 |      6,263       62.63       71.15
          2 |      1,650       16.50       87.65
          3 |        387        3.87       91.52
          9 |        105        1.05       92.57
          . |        743        7.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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