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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        371        3.71        3.71
          1 |        297        2.97        6.68
          2 |        359        3.59       10.27
          3 |        226        2.26       12.53
          4 |        245        2.45       14.98
          5 |        342        3.42       18.40
          6 |        366        3.66       22.06
          7 |        336        3.36       25.42
          8 |        237        2.37       27.79
          9 |        312        3.12       30.91
         10 |        310        3.10       34.01
         11 |        335        3.35       37.36
         12 |        422        4.22       41.58
         13 |        428        4.28       45.86
         14 |        483        4.83       50.69
         15 |        545        5.45       56.14
         16 |        495        4.95       61.09
         17 |        566        5.66       66.75
         18 |        681        6.81       73.56
         19 |        507        5.07       78.63
         20 |        697        6.97       85.60
         21 |        569        5.69       91.29
         22 |        440        4.40       95.69
         23 |        348        3.48       99.17
         99 |         83        0.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016