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

   not_hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        365        3.65        3.65
          1 |        187        1.87        5.52
          2 |        198        1.98        7.50
          3 |        119        1.19        8.69
          4 |        118        1.18        9.87
          5 |        125        1.25       11.12
          6 |        196        1.96       13.08
          7 |        196        1.96       15.04
          8 |        169        1.69       16.73
          9 |        145        1.45       18.18
         10 |        193        1.93       20.11
         11 |        174        1.74       21.85
         12 |        199        1.99       23.84
         13 |        203        2.03       25.87
         14 |        237        2.37       28.24
         15 |        256        2.56       30.80
         16 |        280        2.80       33.60
         17 |        286        2.86       36.46
         18 |        285        2.85       39.31
         19 |        279        2.79       42.10
         20 |        273        2.73       44.83
         21 |        276        2.76       47.59
         22 |        240        2.40       49.99
         23 |        224        2.24       52.23
         24 |          2        0.02       52.25
         99 |      4,775       47.75      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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