Frequencies for hour variable in accident dataset :

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         18        4.69        4.69
          1 |         14        3.65        8.33
          2 |         18        4.69       13.02
          3 |          9        2.34       15.36
          4 |         12        3.12       18.49
          5 |         23        5.99       24.48
          6 |         16        4.17       28.65
          7 |          6        1.56       30.21
          8 |          8        2.08       32.29
          9 |         13        3.39       35.68
         10 |          8        2.08       37.76
         11 |         11        2.86       40.63
         12 |         16        4.17       44.79
         13 |         11        2.86       47.66
         14 |         10        2.60       50.26
         15 |          9        2.34       52.60
         16 |         15        3.91       56.51
         17 |          8        2.08       58.59
         18 |         24        6.25       64.84
         19 |         41       10.68       75.52
         20 |         26        6.77       82.29
         21 |         21        5.47       87.76
         22 |         25        6.51       94.27
         23 |         19        4.95       99.22
         24 |          3        0.78      100.00
------------+-----------------------------------
      Total |        384      100.00

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