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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        390        3.90        3.90
          1 |        428        4.28        8.18
          2 |        376        3.76       11.94
          3 |        289        2.89       14.83
          4 |        227        2.27       17.10
          5 |        276        2.76       19.86
          6 |        353        3.53       23.39
          7 |        355        3.55       26.94
          8 |        292        2.92       29.86
          9 |        298        2.98       32.84
         10 |        315        3.15       35.99
         11 |        358        3.58       39.57
         12 |        391        3.91       43.48
         13 |        426        4.26       47.74
         14 |        463        4.63       52.37
         15 |        513        5.13       57.50
         16 |        538        5.38       62.88
         17 |        554        5.54       68.42
         18 |        555        5.55       73.97
         19 |        543        5.43       79.40
         20 |        525        5.25       84.65
         21 |        500        5.00       89.65
         22 |        490        4.90       94.55
         23 |        431        4.31       98.86
         24 |          7        0.07       98.93
         99 |        107        1.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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