Frequencies for first 10,000 rows of rail variable in accident dataset : Rail Grade | Crossing | Identifier | Freq. Percent Cum. ------------+----------------------------------- 000000 | 1 0.01 0.01 0000000 | 9,964 99.64 99.65 066955m | 1 0.01 99.66 0726305 | 1 0.01 99.67 121003L | 1 0.01 99.68 176909P | 1 0.01 99.69 176940B | 1 0.01 99.70 206571U | 1 0.01 99.71 279854R | 1 0.01 99.72 289004D | 1 0.01 99.73 351290O | 1 0.01 99.74 372184D | 1 0.01 99.75 434963V | 1 0.01 99.76 438550P | 1 0.01 99.77 450506E | 1 0.01 99.78 478713F | 1 0.01 99.79 479355C | 1 0.01 99.80 538974x | 1 0.01 99.81 608945G | 1 0.01 99.82 637383S | 1 0.01 99.83 638278U | 1 0.01 99.84 640128L | 1 0.01 99.85 725393P | 1 0.01 99.86 725396K | 1 0.01 99.87 727747N | 1 0.01 99.88 727820O | 1 0.01 99.89 728005Y | 1 0.01 99.90 732723K | 1 0.01 99.91 741299S | 1 0.01 99.92 742093V | 1 0.01 99.93 750803b | 1 0.01 99.94 752351A | 1 0.01 99.95 755011y | 1 0.01 99.96 760723K | 1 0.01 99.97 762291v | 1 0.01 99.98 78910M | 1 0.01 99.99 811319V | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016