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

 Crash Time |
     (HOUR) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        405        4.05        4.05
          1 |        349        3.49        7.54
          2 |        364        3.64       11.18
          3 |        265        2.65       13.83
          4 |        252        2.52       16.35
          5 |        275        2.75       19.10
          6 |        354        3.54       22.64
          7 |        328        3.28       25.92
          8 |        308        3.08       29.00
          9 |        340        3.40       32.40
         10 |        313        3.13       35.53
         11 |        358        3.58       39.11
         12 |        454        4.54       43.65
         13 |        406        4.06       47.71
         14 |        496        4.96       52.67
         15 |        499        4.99       57.66
         16 |        543        5.43       63.09
         17 |        622        6.22       69.31
         18 |        564        5.64       74.95
         19 |        523        5.23       80.18
         20 |        526        5.26       85.44
         21 |        475        4.75       90.19
         22 |        452        4.52       94.71
         23 |        396        3.96       98.67
         99 |        133        1.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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