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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        400        4.00        4.00
          1 |        414        4.14        8.14
          2 |        321        3.21       11.35
          3 |        233        2.33       13.68
          4 |        209        2.09       15.77
          5 |        275        2.75       18.52
          6 |        347        3.47       21.99
          7 |        301        3.01       25.00
          8 |        262        2.62       27.62
          9 |        312        3.12       30.74
         10 |        335        3.35       34.09
         11 |        370        3.70       37.79
         12 |        413        4.13       41.92
         13 |        467        4.67       46.59
         14 |        511        5.11       51.70
         15 |        533        5.33       57.03
         16 |        531        5.31       62.34
         17 |        577        5.77       68.11
         18 |        592        5.92       74.03
         19 |        559        5.59       79.62
         20 |        535        5.35       84.97
         21 |        487        4.87       89.84
         22 |        480        4.80       94.64
         23 |        427        4.27       98.91
         24 |          7        0.07       98.98
         99 |        102        1.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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