Frequencies for first 10,000 rows of repeac variable in natl1995 dataset : Repeat | C-section | Freq. Percent Cum. ------------+----------------------------------- 1 | 807 8.07 8.07 2 | 9,183 91.83 99.90 9 | 10 0.10 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015