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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        881        8.81        8.81
          1 |      6,232       62.32       71.13
          2 |      1,793       17.93       89.06
          3 |        345        3.45       92.51
          9 |          6        0.06       92.57
          . |        743        7.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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