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

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        615        6.15        6.15
          1 |      6,959       69.59       75.74
          2 |      1,859       18.59       94.33
          3 |        474        4.74       99.07
          9 |         93        0.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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