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

    Vehicle |
       Role |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      2,214       22.14       22.14
          1 |      4,751       47.51       69.65
          2 |      2,001       20.01       89.66
          3 |        214        2.14       91.80
          9 |         28        0.28       92.08
          . |        792        7.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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