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

       hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        377        3.77        3.77
          1 |        400        4.00        7.77
          2 |        350        3.50       11.27
          3 |        288        2.88       14.15
          4 |        233        2.33       16.48
          5 |        284        2.84       19.32
          6 |        395        3.95       23.27
          7 |        320        3.20       26.47
          8 |        308        3.08       29.55
          9 |        290        2.90       32.45
         10 |        308        3.08       35.53
         11 |        398        3.98       39.51
         12 |        375        3.75       43.26
         13 |        401        4.01       47.27
         14 |        468        4.68       51.95
         15 |        562        5.62       57.57
         16 |        515        5.15       62.72
         17 |        553        5.53       68.25
         18 |        566        5.66       73.91
         19 |        547        5.47       79.38
         20 |        565        5.65       85.03
         21 |        528        5.28       90.31
         22 |        439        4.39       94.70
         23 |        418        4.18       98.88
         24 |          7        0.07       98.95
         99 |        105        1.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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