Frequencies for first 10,000 rows of sch_bus variable in person dataset : School Bus | Related | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,996 99.96 99.96 1 | 4 0.04 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016