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

   PREVIOUS |
   SPEEDING |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,699       76.99       76.99
          1 |      1,278       12.78       89.77
          2 |        364        3.64       93.41
          3 |        108        1.08       94.49
          4 |         31        0.31       94.80
          5 |         11        0.11       94.91
          6 |          3        0.03       94.94
          7 |          3        0.03       94.97
         99 |        441        4.41       99.38
          . |         62        0.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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