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

   not_hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        475        4.75        4.75
          1 |        238        2.38        7.13
          2 |        199        1.99        9.12
          3 |        157        1.57       10.69
          4 |         98        0.98       11.67
          5 |        127        1.27       12.94
          6 |        178        1.78       14.72
          7 |        176        1.76       16.48
          8 |        134        1.34       17.82
          9 |        142        1.42       19.24
         10 |        168        1.68       20.92
         11 |        181        1.81       22.73
         12 |        179        1.79       24.52
         13 |        183        1.83       26.35
         14 |        252        2.52       28.87
         15 |        254        2.54       31.41
         16 |        275        2.75       34.16
         17 |        234        2.34       36.50
         18 |        301        3.01       39.51
         19 |        287        2.87       42.38
         20 |        285        2.85       45.23
         21 |        280        2.80       48.03
         22 |        240        2.40       50.43
         23 |        253        2.53       52.96
         24 |          3        0.03       52.99
         99 |      4,701       47.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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