Frequencies for first 10,000 rows of f_tobac variable in natl2003 dataset : Tobacco use | U | Freq. Percent Cum. ------------+----------------------------------- 0 | 7 0.07 0.07 1 | 9,993 99.93 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015