Frequencies for first 10,000 rows of tow_veh variable in person dataset : Towed | Trailing | Unit | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,163 91.63 91.63 1 | 56 0.56 92.19 . | 781 7.81 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Apr 2016