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

 Crash Time |
     (Hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        350        3.50        3.50
          1 |        336        3.36        6.86
          2 |        415        4.15       11.01
          3 |        256        2.56       13.57
          4 |        222        2.22       15.79
          5 |        303        3.03       18.82
          6 |        360        3.60       22.42
          7 |        328        3.28       25.70
          8 |        291        2.91       28.61
          9 |        327        3.27       31.88
         10 |        328        3.28       35.16
         11 |        356        3.56       38.72
         12 |        453        4.53       43.25
         13 |        462        4.62       47.87
         14 |        480        4.80       52.67
         15 |        489        4.89       57.56
         16 |        558        5.58       63.14
         17 |        588        5.88       69.02
         18 |        593        5.93       74.95
         19 |        543        5.43       80.38
         20 |        525        5.25       85.63
         21 |        493        4.93       90.56
         22 |        419        4.19       94.75
         23 |        422        4.22       98.97
         99 |        103        1.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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