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

   not_hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        274        2.74        2.74
          1 |        185        1.85        4.59
          2 |        182        1.82        6.41
          3 |        123        1.23        7.64
          4 |        110        1.10        8.74
          5 |        156        1.56       10.30
          6 |        168        1.68       11.98
          7 |        181        1.81       13.79
          8 |        138        1.38       15.17
          9 |        114        1.14       16.31
         10 |        127        1.27       17.58
         11 |        176        1.76       19.34
         12 |        159        1.59       20.93
         13 |        202        2.02       22.95
         14 |        202        2.02       24.97
         15 |        228        2.28       27.25
         16 |        245        2.45       29.70
         17 |        223        2.23       31.93
         18 |        220        2.20       34.13
         19 |        250        2.50       36.63
         20 |        264        2.64       39.27
         21 |        246        2.46       41.73
         22 |        233        2.33       44.06
         23 |        222        2.22       46.28
         24 |          1        0.01       46.29
         99 |      5,371       53.71      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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