Frequencies for first 10,000 rows of f_uld_breech variable in natl2009 dataset : Breech | (uld_breech | ) U;R | Freq. Percent Cum. ------------+----------------------------------- 0 | 40 0.40 0.40 1 | 9,960 99.60 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015