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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        920        9.20        9.20
          1 |      5,539       55.39       64.59
          2 |      2,413       24.13       88.72
          3 |        463        4.63       93.35
          9 |         96        0.96       94.31
          . |        569        5.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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