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

   not_hour |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        484        4.84        4.84
          1 |        248        2.48        7.32
          2 |        240        2.40        9.72
          3 |        123        1.23       10.95
          4 |        104        1.04       11.99
          5 |        117        1.17       13.16
          6 |        178        1.78       14.94
          7 |        173        1.73       16.67
          8 |        144        1.44       18.11
          9 |        155        1.55       19.66
         10 |        147        1.47       21.13
         11 |        180        1.80       22.93
         12 |        199        1.99       24.92
         13 |        213        2.13       27.05
         14 |        269        2.69       29.74
         15 |        249        2.49       32.23
         16 |        285        2.85       35.08
         17 |        275        2.75       37.83
         18 |        339        3.39       41.22
         19 |        285        2.85       44.07
         20 |        304        3.04       47.11
         21 |        285        2.85       49.96
         22 |        261        2.61       52.57
         23 |        280        2.80       55.37
         24 |          1        0.01       55.38
         99 |      4,462       44.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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