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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        404        4.04        4.04
          1 |        390        3.90        7.94
          2 |        376        3.76       11.70
          3 |        296        2.96       14.66
          4 |        268        2.68       17.34
          5 |        354        3.54       20.88
          6 |        397        3.97       24.85
          7 |        325        3.25       28.10
          8 |        246        2.46       30.56
          9 |        276        2.76       33.32
         10 |        300        3.00       36.32
         11 |        331        3.31       39.63
         12 |        351        3.51       43.14
         13 |        374        3.74       46.88
         14 |        432        4.32       51.20
         15 |        470        4.70       55.90
         16 |        431        4.31       60.21
         17 |        551        5.51       65.72
         18 |        624        6.24       71.96
         19 |        570        5.70       77.66
         20 |        639        6.39       84.05
         21 |        596        5.96       90.01
         22 |        505        5.05       95.06
         23 |        413        4.13       99.19
         99 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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