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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        501        5.01        5.01
          1 |        497        4.97        9.98
          2 |        459        4.59       14.57
          3 |        282        2.82       17.39
          4 |        237        2.37       19.76
          5 |        263        2.63       22.39
          6 |        299        2.99       25.38
          7 |        316        3.16       28.54
          8 |        268        2.68       31.22
          9 |        224        2.24       33.46
         10 |        258        2.58       36.04
         11 |        320        3.20       39.24
         12 |        338        3.38       42.62
         13 |        371        3.71       46.33
         14 |        429        4.29       50.62
         15 |        530        5.30       55.92
         16 |        489        4.89       60.81
         17 |        565        5.65       66.46
         18 |        622        6.22       72.68
         19 |        535        5.35       78.03
         20 |        530        5.30       83.33
         21 |        563        5.63       88.96
         22 |        506        5.06       94.02
         23 |        505        5.05       99.07
         24 |          3        0.03       99.10
         99 |         90        0.90      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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