Frequencies for first 10,000 rows of rail variable in accident dataset : rail grade | crossing | identifier | Freq. Percent Cum. ------------+----------------------------------- 0000000 | 9,957 99.57 99.57 028973u | 1 0.01 99.58 029511v | 1 0.01 99.59 057349H | 1 0.01 99.60 245392G | 1 0.01 99.61 253278C | 1 0.01 99.62 254065V | 1 0.01 99.63 271831G | 1 0.01 99.64 294473P | 1 0.01 99.65 340724H | 1 0.01 99.66 349977W | 1 0.01 99.67 425280F | 1 0.01 99.68 434305X | 1 0.01 99.69 434309A | 1 0.01 99.70 439833R | 1 0.01 99.71 441446Y | 1 0.01 99.72 478782N | 1 0.01 99.73 500593A | 1 0.01 99.74 546327H | 1 0.01 99.75 608958H | 1 0.01 99.76 622318S | 1 0.01 99.77 624510D | 1 0.01 99.78 628054U | 1 0.01 99.79 628160C | 1 0.01 99.80 628168G | 1 0.01 99.81 637382K | 1 0.01 99.82 662631D | 1 0.01 99.83 668075W | 1 0.01 99.84 723176H | 1 0.01 99.85 724755V | 1 0.01 99.86 728027Y | 1 0.01 99.87 729216Y | 1 0.01 99.88 733435U | 1 0.01 99.89 752443m | 1 0.01 99.90 787508C | 1 0.01 99.91 818935F | 1 0.01 99.92 853357B | 1 0.01 99.93 917334U | 1 0.01 99.94 9999999 | 6 0.06 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Oct 2016