Frequencies for first 10,000 rows of tow_veh variable in vehicle dataset : vehicle | trailing | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,410 94.10 94.10 1 | 538 5.38 99.48 2 | 30 0.30 99.78 4 | 1 0.01 99.79 5 | 5 0.05 99.84 6 | 8 0.08 99.92 9 | 8 0.08 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Oct 2016