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

   previous |
   recorded |
    crashes |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,130       81.30       81.30
          1 |        871        8.71       90.01
          2 |        124        1.24       91.25
          3 |         15        0.15       91.40
          4 |          3        0.03       91.43
          7 |          1        0.01       91.44
          8 |          2        0.02       91.46
         98 |        398        3.98       95.44
         99 |        392        3.92       99.36
        998 |         64        0.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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