Frequencies for first 10,000 rows of alcohol variable in natlterr2001 dataset : Alcohol Use | During | Pregnancy | Freq. Percent Cum. ------------+----------------------------------- 1 | 7 0.07 0.07 2 | 9,972 99.72 99.79 9 | 21 0.21 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015