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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        951        9.51        9.51
          1 |      6,072       60.72       70.23
          2 |      1,731       17.31       87.54
          3 |        441        4.41       91.95
          9 |         78        0.78       92.73
          . |        727        7.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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