Frequencies for first 10,000 rows of f_ca_gastro variable in natlterr2009 dataset : Gastroschis | is | (ca_gast) R | Freq. Percent Cum. ------------+----------------------------------- 0 | 2,460 24.60 24.60 1 | 7,540 75.40 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015