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

   previous |
   recorded |
    crashes |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,241       82.41       82.41
          1 |        751        7.51       89.92
          2 |         99        0.99       90.91
          3 |         12        0.12       91.03
          4 |          5        0.05       91.08
          5 |          2        0.02       91.10
          6 |          1        0.01       91.11
         98 |        451        4.51       95.62
         99 |        369        3.69       99.31
        998 |         69        0.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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