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

   not_hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        566        5.66        5.66
          1 |        233        2.33        7.99
          2 |        225        2.25       10.24
          3 |        146        1.46       11.70
          4 |        112        1.12       12.82
          5 |        114        1.14       13.96
          6 |        177        1.77       15.73
          7 |        174        1.74       17.47
          8 |        148        1.48       18.95
          9 |        125        1.25       20.20
         10 |        126        1.26       21.46
         11 |        156        1.56       23.02
         12 |        154        1.54       24.56
         13 |        176        1.76       26.32
         14 |        194        1.94       28.26
         15 |        260        2.60       30.86
         16 |        240        2.40       33.26
         17 |        253        2.53       35.79
         18 |        282        2.82       38.61
         19 |        248        2.48       41.09
         20 |        243        2.43       43.52
         21 |        266        2.66       46.18
         22 |        245        2.45       48.63
         23 |        234        2.34       50.97
         24 |          1        0.01       50.98
         99 |      4,902       49.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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