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

   PREVIOUS |
  ACCIDENTS |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,578       75.78       75.78
          1 |      1,306       13.06       88.84
          2 |        202        2.02       90.86
          3 |         43        0.43       91.29
          4 |         10        0.10       91.39
          5 |          1        0.01       91.40
         98 |        408        4.08       95.48
         99 |        373        3.73       99.21
          . |         79        0.79      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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