Frequencies for first 10,000 rows of rectal variable in natl1992 dataset : Rectal | atresia/ste | nosis | Freq. Percent Cum. ------------+----------------------------------- 2 | 9,997 99.97 99.97 9 | 3 0.03 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015