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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        896        8.96        8.96
          1 |      6,339       63.39       72.35
          2 |      1,683       16.83       89.18
          3 |        316        3.16       92.34
          9 |         20        0.20       92.54
          . |        746        7.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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