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

 crash time |
     (hour) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        449        4.49        4.49
          1 |        366        3.66        8.15
          2 |        321        3.21       11.36
          3 |        230        2.30       13.66
          4 |        193        1.93       15.59
          5 |        331        3.31       18.90
          6 |        316        3.16       22.06
          7 |        324        3.24       25.30
          8 |        250        2.50       27.80
          9 |        250        2.50       30.30
         10 |        303        3.03       33.33
         11 |        410        4.10       37.43
         12 |        487        4.87       42.30
         13 |        423        4.23       46.53
         14 |        464        4.64       51.17
         15 |        569        5.69       56.86
         16 |        485        4.85       61.71
         17 |        616        6.16       67.87
         18 |        601        6.01       73.88
         19 |        541        5.41       79.29
         20 |        566        5.66       84.95
         21 |        549        5.49       90.44
         22 |        374        3.74       94.18
         23 |        449        4.49       98.67
         99 |        133        1.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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