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

   PREVIOUS |
   SPEEDING |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,705       77.05       77.05
          1 |      1,178       11.78       88.83
          2 |        306        3.06       91.89
          3 |        112        1.12       93.01
          4 |         33        0.33       93.34
          5 |          2        0.02       93.36
          6 |          3        0.03       93.39
          7 |          2        0.02       93.41
         99 |        599        5.99       99.40
          . |         60        0.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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