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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        378        3.78        3.78
          1 |        459        4.59        8.37
          2 |        471        4.71       13.08
          3 |        293        2.93       16.01
          4 |        250        2.50       18.51
          5 |        294        2.94       21.45
          6 |        367        3.67       25.12
          7 |        301        3.01       28.13
          8 |        260        2.60       30.73
          9 |        266        2.66       33.39
         10 |        280        2.80       36.19
         11 |        370        3.70       39.89
         12 |        392        3.92       43.81
         13 |        377        3.77       47.58
         14 |        440        4.40       51.98
         15 |        503        5.03       57.01
         16 |        483        4.83       61.84
         17 |        520        5.20       67.04
         18 |        580        5.80       72.84
         19 |        532        5.32       78.16
         20 |        575        5.75       83.91
         21 |        534        5.34       89.25
         22 |        492        4.92       94.17
         23 |        437        4.37       98.54
         24 |          7        0.07       98.61
         99 |        139        1.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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