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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        544        5.44        5.44
          1 |      6,478       64.78       70.22
          2 |      1,905       19.05       89.27
          3 |        248        2.48       91.75
          9 |         44        0.44       92.19
          . |        781        7.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016