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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        437        4.37        4.37
          1 |        352        3.52        7.89
          2 |        406        4.06       11.95
          3 |        305        3.05       15.00
          4 |        249        2.49       17.49
          5 |        315        3.15       20.64
          6 |        368        3.68       24.32
          7 |        318        3.18       27.50
          8 |        285        2.85       30.35
          9 |        276        2.76       33.11
         10 |        326        3.26       36.37
         11 |        354        3.54       39.91
         12 |        392        3.92       43.83
         13 |        376        3.76       47.59
         14 |        410        4.10       51.69
         15 |        454        4.54       56.23
         16 |        483        4.83       61.06
         17 |        565        5.65       66.71
         18 |        580        5.80       72.51
         19 |        585        5.85       78.36
         20 |        587        5.87       84.23
         21 |        544        5.44       89.67
         22 |        516        5.16       94.83
         23 |        419        4.19       99.02
         99 |         98        0.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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