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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        966        9.66        9.66
          1 |      6,094       60.94       70.60
          2 |      1,770       17.70       88.30
          3 |        434        4.34       92.64
          9 |         69        0.69       93.33
          . |        667        6.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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