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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        416        4.16        4.16
          1 |        444        4.44        8.60
          2 |        461        4.61       13.21
          3 |        281        2.81       16.02
          4 |        232        2.32       18.34
          5 |        306        3.06       21.40
          6 |        347        3.47       24.87
          7 |        351        3.51       28.38
          8 |        245        2.45       30.83
          9 |        285        2.85       33.68
         10 |        306        3.06       36.74
         11 |        334        3.34       40.08
         12 |        369        3.69       43.77
         13 |        411        4.11       47.88
         14 |        485        4.85       52.73
         15 |        539        5.39       58.12
         16 |        458        4.58       62.70
         17 |        552        5.52       68.22
         18 |        538        5.38       73.60
         19 |        510        5.10       78.70
         20 |        556        5.56       84.26
         21 |        525        5.25       89.51
         22 |        474        4.74       94.25
         23 |        460        4.60       98.85
         24 |          9        0.09       98.94
         99 |        106        1.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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