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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,058       10.58       10.58
          1 |      6,365       63.65       74.23
          2 |      1,534       15.34       89.57
          3 |        266        2.66       92.23
          9 |          1        0.01       92.24
          . |        776        7.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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