Frequencies for first 10,000 rows of hour variable in vehicle dataset :

 Crash Time |
     (Hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        358        3.58        3.58
          1 |        376        3.76        7.34
          2 |        373        3.73       11.07
          3 |        278        2.78       13.85
          4 |        220        2.20       16.05
          5 |        291        2.91       18.96
          6 |        369        3.69       22.65
          7 |        351        3.51       26.16
          8 |        300        3.00       29.16
          9 |        340        3.40       32.56
         10 |        350        3.50       36.06
         11 |        387        3.87       39.93
         12 |        477        4.77       44.70
         13 |        418        4.18       48.88
         14 |        515        5.15       54.03
         15 |        497        4.97       59.00
         16 |        543        5.43       64.43
         17 |        620        6.20       70.63
         18 |        520        5.20       75.83
         19 |        480        4.80       80.63
         20 |        527        5.27       85.90
         21 |        472        4.72       90.62
         22 |        470        4.70       95.32
         23 |        373        3.73       99.05
         99 |         95        0.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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