Frequencies for first 10,000 rows of cleftlp variable in natl1999 dataset : Cleft | lip/palate | Freq. Percent Cum. ------------+----------------------------------- 1 | 7 0.07 0.07 2 | 9,993 99.93 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015