Frequencies for first 10,000 rows of tow_veh variable in person dataset : Towed | Trailing | Unit | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,040 90.40 90.40 1 | 85 0.85 91.25 . | 875 8.75 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Apr 2016