Frequencies for first 10,000 rows of sch_bus variable in person dataset : SCHOOLBUS | RELATED | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,917 99.17 99.17 1 | 83 0.83 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016