Frequencies for first 10,000 rows of f_uob_tocol variable in natlterr2007 dataset : Tocolysis U | Freq. Percent Cum. ------------+----------------------------------- 0 | 11 0.11 0.11 1 | 9,989 99.89 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015