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

  RAIL XING |
         ID |      Freq.     Percent        Cum.
------------+-----------------------------------
    0000000 |      9,946       99.46       99.46
    0010515 |          1        0.01       99.47
    003211G |          1        0.01       99.48
    025650C |          1        0.01       99.49
    026827V |          1        0.01       99.50
    028310B |          1        0.01       99.51
    028380R |          1        0.01       99.52
    028739S |          1        0.01       99.53
    176281Y |          1        0.01       99.54
    272593U |          1        0.01       99.55
    351460V |          1        0.01       99.56
    352163F |          1        0.01       99.57
    425204M |          1        0.01       99.58
    425321H |          1        0.01       99.59
    433729B |          1        0.01       99.60
    437817A |          1        0.01       99.61
    437974T |          1        0.01       99.62
    438232D |          1        0.01       99.63
    438575K |          1        0.01       99.64
    4389092 |          1        0.01       99.65
    439848F |          1        0.01       99.66
    639423U |          1        0.01       99.67
    664091S |          1        0.01       99.68
    667563w |          1        0.01       99.69
    668064J |          1        0.01       99.70
    727088L |          1        0.01       99.71
    727829V |          1        0.01       99.72
    731767G |          1        0.01       99.73
    741105J |          1        0.01       99.74
    741411B |          1        0.01       99.75
    742082H |          1        0.01       99.76
    748706S |          1        0.01       99.77
    749720R |          1        0.01       99.78
    752729J |          1        0.01       99.79
    753601N |          1        0.01       99.80
    755155D |          1        0.01       99.81
    755164C |          1        0.01       99.82
    760745K |          1        0.01       99.83
    789706E |          1        0.01       99.84
    804329J |          1        0.01       99.85
    804860T |          1        0.01       99.86
    811005Y |          1        0.01       99.87
    831161P |          1        0.01       99.88
    831205M |          1        0.01       99.89
    842785L |          1        0.01       99.90
    8720990 |          1        0.01       99.91
    906015V |          1        0.01       99.92
    9999999 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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