Frequencies for first 10,000 rows of omphalo variable in natl1999 dataset : Omphalocele | /Gastroschi | sis | Freq. Percent Cum. ------------+----------------------------------- 1 | 2 0.02 0.02 2 | 9,998 99.98 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015