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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        403        4.03        4.03
          1 |        428        4.28        8.31
          2 |        404        4.04       12.35
          3 |        282        2.82       15.17
          4 |        226        2.26       17.43
          5 |        252        2.52       19.95
          6 |        293        2.93       22.88
          7 |        336        3.36       26.24
          8 |        268        2.68       28.92
          9 |        271        2.71       31.63
         10 |        316        3.16       34.79
         11 |        341        3.41       38.20
         12 |        397        3.97       42.17
         13 |        370        3.70       45.87
         14 |        450        4.50       50.37
         15 |        542        5.42       55.79
         16 |        475        4.75       60.54
         17 |        586        5.86       66.40
         18 |        606        6.06       72.46
         19 |        575        5.75       78.21
         20 |        554        5.54       83.75
         21 |        548        5.48       89.23
         22 |        489        4.89       94.12
         23 |        475        4.75       98.87
         24 |          8        0.08       98.95
         99 |        105        1.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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