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

   previous |
   recorded |
    crashes |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,332       83.32       83.32
          1 |        736        7.36       90.68
          2 |         90        0.90       91.58
          3 |         12        0.12       91.70
          4 |          2        0.02       91.72
         98 |        428        4.28       96.00
         99 |        339        3.39       99.39
        998 |         61        0.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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