Frequencies for first 10,000 rows of tobacco variable in natlterr1996 dataset : Tobacco Use | During | Pregnancy | Freq. Percent Cum. ------------+----------------------------------- 1 | 114 1.14 1.14 2 | 9,886 98.86 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015