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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        432        4.32        4.32
          1 |        351        3.51        7.83
          2 |        398        3.98       11.81
          3 |        315        3.15       14.96
          4 |        242        2.42       17.38
          5 |        304        3.04       20.42
          6 |        358        3.58       24.00
          7 |        344        3.44       27.44
          8 |        283        2.83       30.27
          9 |        285        2.85       33.12
         10 |        327        3.27       36.39
         11 |        360        3.60       39.99
         12 |        397        3.97       43.96
         13 |        435        4.35       48.31
         14 |        431        4.31       52.62
         15 |        501        5.01       57.63
         16 |        479        4.79       62.42
         17 |        511        5.11       67.53
         18 |        563        5.63       73.16
         19 |        528        5.28       78.44
         20 |        553        5.53       83.97
         21 |        568        5.68       89.65
         22 |        507        5.07       94.72
         23 |        431        4.31       99.03
         99 |         97        0.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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