Frequencies for first 10,000 rows of tow_veh variable in person dataset : Towed | Trailing | Unit | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,075 90.75 90.75 1 | 63 0.63 91.38 . | 862 8.62 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Apr 2016