Frequencies for first 10,000 rows of clubfoot variable in natl1992 dataset : Club foot | Freq. Percent Cum. ------------+----------------------------------- 1 | 4 0.04 0.04 2 | 9,993 99.93 99.97 9 | 3 0.03 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015