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

  RAIL XING |
         ID |      Freq.     Percent        Cum.
------------+-----------------------------------
    0000000 |      9,963       99.63       99.63
    003263Y |          1        0.01       99.64
    003377L |          2        0.02       99.66
    026526A |          1        0.01       99.67
    028395F |          1        0.01       99.68
    253272L |          1        0.01       99.69
    271820U |          1        0.01       99.70
    272375M |          1        0.01       99.71
    279506M |          1        0.01       99.72
    325190D |          1        0.01       99.73
    339668G |          1        0.01       99.74
    434286V |          1        0.01       99.75
    438546A |          1        0.01       99.76
    621525H |          1        0.01       99.77
    621538J |          1        0.01       99.78
    622056M |          1        0.01       99.79
    622067A |          1        0.01       99.80
    622317K |          1        0.01       99.81
    622736h |          1        0.01       99.82
    628159H |          1        0.01       99.83
    628165L |          1        0.01       99.84
    628177F |          1        0.01       99.85
    638156P |          1        0.01       99.86
    667235E |          1        0.01       99.87
    717710W |          1        0.01       99.88
    725433K |          1        0.01       99.89
    726981B |          1        0.01       99.90
    727760C |          1        0.01       99.91
    732745K |          1        0.01       99.92
    741120L |          1        0.01       99.93
    745665E |          1        0.01       99.94
    750086F |          1        0.01       99.95
    751678U |          1        0.01       99.96
    788987M |          1        0.01       99.97
    9999999 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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