Frequencies for first 10,000 rows of tow_veh variable in vehicle dataset : TOWED | TRAILING | UNIT | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,268 92.68 92.68 1 | 544 5.44 98.12 2 | 58 0.58 98.70 4 | 1 0.01 98.71 5 | 4 0.04 98.75 9 | 125 1.25 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016