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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        399        3.99        3.99
          1 |        313        3.13        7.12
          2 |        391        3.91       11.03
          3 |        236        2.36       13.39
          4 |        206        2.06       15.45
          5 |        322        3.22       18.67
          6 |        373        3.73       22.40
          7 |        340        3.40       25.80
          8 |        307        3.07       28.87
          9 |        273        2.73       31.60
         10 |        321        3.21       34.81
         11 |        389        3.89       38.70
         12 |        407        4.07       42.77
         13 |        409        4.09       46.86
         14 |        448        4.48       51.34
         15 |        480        4.80       56.14
         16 |        529        5.29       61.43
         17 |        658        6.58       68.01
         18 |        601        6.01       74.02
         19 |        566        5.66       79.68
         20 |        596        5.96       85.64
         21 |        505        5.05       90.69
         22 |        478        4.78       95.47
         23 |        365        3.65       99.12
         99 |         88        0.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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