Frequencies for first 10,000 rows of f_uab_venl30 variable in natlterr2006 dataset : Assisted | Ventilation | <30 min | (uab_venl30 | ) U | Freq. Percent Cum. ------------+----------------------------------- 0 | 5,186 51.86 51.86 1 | 4,814 48.14 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015